A Hugh Cassidy was allegedly struck on the head during an argument while returning from a fair in Boho in 1829. Perhaps Owen may also have had a brother or cousin named Hugh? 
It is not yet confirmed that Owen is the father of William.
Whilst I have removed myself as profile manager for this person, it has only been due to watchlist considerations. Please do not hesitate to contact Veronica Williams should you wish to collaborate on this profile.
Thought to possibly be a brother or cousin of Stephen Cassidy. yDNA results have confirmed a relationship, but now suggests they were more likely to be first or second cousins.
YDNA results Haplogroup I2b1 - origins in Northern France. I- M223.
↑ Paternal relationship is confirmed through Y-chromosome DNA testing. Cassidy-453 and Cassidy-1188 match on 35 out of 37 markers (see YSearch IDs 9EJCS and ZQYVC) thereby confirming their relationship as fifth cousins and their direct paternal lines back to their MRCA as yet Unnamed CASSIDY.
It may be possible to confirm family relationships with Owen by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree: