... MONDAY 5: I went with H. Ayers and Allen to the river and washed our clothes. ... 
<Cathryn's note: Of the 3 men surnamed Allen who enlisted in Company D of the 105th OVI, only Minor H. Allen remains in the ranks on this date.>
United States Congressional Serial Set, Volume 2519
This book, published by the U.S. Government Printing Office in 1888 contains “The Committee on Pensions, to who was referred the bill (S 338), granting a pension to Samuel Brooks.” What follows is synopsis.
Samuel Brooks began receiving a military pension on November 21, 1866 due to wounds he received at Fayetteville North Carolina on March 16, 1865. On December 1, 1870, his pension was "dropped without notice and without opportunity to answer or explain the attacks upon his character embodied in a report of a special agent of the Pension Office." The agent recommended Brooks' name "be stricken from the pension-roll" based on the testimony of four men, namely James H. Taylor, Francis M. Webster, Minor Allen and Almon Grover. According to their testimony, Brooks was intoxicated when he returned from guard duty. He did not accompany his unit "on the move", rather he went off and was wounded in a house of ill fame, rather than while on duty.
Specific passages in the document referencing Almon Grover are:
Four men, Taylor, Webster, Allen and Grover, were found, who under the immunity of secrecy, indorsed (sic) the statement reported to the detective to the Commissioner of Pensions on October 15, 1870. The verbal statements of these men were forwarded to the Commissioner May 1, 1872, and were made to plan an important part in determining an appeal taken by the claimant from the Commissioner's decision of suspension to the Secretary of the Interior, which appeal was decided on November 30, 1872. This decision, after reviewing the whole case, concludes as follows:
Applying the principle herein before alluded to, I am clearly of opinion that the sworn testimony in support of the claim outweighs the unsworn testimony against it, and therefore the pension should be restored to the claimant. I do not deem the discrepancies existing between the two declarations of the claimant to be a sufficient ground for denying him a pension. ...
Before the case is fully disposed of, however, I would suggest that every effort be made by your office to obtain the affidavits of Taylor, Grover, Allen and Webster as to their knowledge of the circumstances as stated by them to the special agent of your office. If they will swear what they have stated the weight of evidence will include against the claimant and justify a continued suspension of Brooks's pension, or rather an entire cessation thereof.
The affidavits of the parties in question were secured by the detective, McColm, and transmitted to the safe custody of the secret-service division. The animus which moved the detective, and his conception of duty in a case of antagonism between a soldier and his own official superior, are indicated in the following extract from his report of January 29, 1873, transmitting to the Commissioner of Pensions the last of the four affidavits of which he was sent in quest:
The affidavit of Grover completes the testimony called for by the honorable Acting Secretary of the Interior, in order that the weight of testimony made under oath, that of Taylor, Allen, Webster, and Grover, may sustain the decision of the honorable Commissioner of Pensions in this case. ...
The summary of testimony given before Examiner Keeney, dated January 21, 1885, follows: ...
Claimant's final statements: ...; and Minor Allen is now, I am informed, residing in San Raphael, Marin County, Cal. He is a most important witness and should be seen and closely questioned. ...
On November 30, 1872, according to the decision of the Acting Secretary of the Interior ..., the sole question remaining open in this case was that of the incurrence of the claimant's wound in the line of duty. The procurement bye the detective, McColm, of the affidavits of the witnesses Taylor, Allen, Webster, and Grover, averring that the claimant, when wounded, was drunk and off duty, decided in the opinion of the Acting Secretary of the Interior, this question against the claimant; and such decision was formally rendered by this official on February 25, 1873. Of the witnesses examined during 1885 and 1886, abstracts of whose testimony are hereinbefore given, many contradicted all, and all contradicted man, of the averments of the four affidavits, on which alone there was found justification for withholding the claimant's pension. These later witnesses, however, furnished only cumulative testimony; for, as has already been shown by the committee, the affidavits of Taylor, Allen, Webster, and Grover contained inherent proofs of their falsity; and what the committee charge, the majority of these four affidavit makers (one of whom is dead, and comprising two out three who are still alive) themselves admit and sustain in their examinations of January, 1885. 
"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6G1-C89 : 26 August 2017), Minor H Allen, San Rafael, Marin, California, United States; citing enumeration district ED 234, sheet 69A, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d.), roll 0068; FHL microfilm 1,254,068.
"United States Civil War Soldiers Index, 1861-1865," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FSML-76X : 4 December 2014), Minor A. Allen, Private, Company D, 105th Regiment, Ohio Infantry, Union; citing NARA microfilm publication M552 (Washington D.C.: National Archives and Records Administration, n.d.), roll 2; FHL microfilm 882,215.
"California Great Registers, 1866-1910," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VYD2-G12 : 4 August 2017), Minor H Allen, 19 Oct 1893; citing Voter Registration, 1005 F St, Sacramento, California, United States, county clerk offices, California; FHL microfilm 978,926.
"United States Records of Headstones of Deceased Union Veterans, 1879-1903," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:V6H3-HNY : 4 December 2014), Minor H Allen, 25 Mar 1894; citing Sacramento, , California, NARA microfilm publication M1845 (Washington D.C.: National Archives and Records Administration, n.d.), roll 1; FHL microfilm 2,155,576.