Denis Carty, the father of Denis Carty, who was married in 1870 is shown as 'deceased' on the marriage certificate. This leaves as small window for notification in the Civil registration system. There is a death of a Denis Carthy aged 50 years in 1867 in Tipperary. Certificate needs to be obtained ie not available online yet.
I'd keep this link in your back pocket OP until we have finished sleuthing.
http://www.rootschat.com/links/01tjb/
Above died in Coolbaurs, Tipperary, Tipperary.
And a Denis McCarthy, age 55, in Clonmel, also 1867.
Some further details, such as exact date of death, available in transcripts on FamilySearch. Sometimes these transcripts give other useful details such as the name of the informant, and relationship, but not in these two cases.