It may be possible to confirm family relationships by comparing test results with Michael or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
AncestryDNA Paternal Lineage (discontinued) 46 markers, haplogroup R1b, Ancestry member mclynn28 +
Family Tree DNA Y-DNA Test 111 markers, haplogroup R-U198, FTDNA kit #B1172
Mitochondrial DNA test-takers in the direct maternal line:
AncestryDNA Maternal Lineage (discontinued) Other, haplogroup U, Ancestry member mclynn28