Could this be a mistake in a marriage register? (hopefully)

p15574

Are mistakes common in church marriage registers? I am on the trail of someone for whom almost all the bits fit - including direct oral family information that was later corroborated by details of this person's children. Basically, I'm looking into this child, born in Donegal in 1875. Based on the corroborating evidence, I'm 99% sure that this is his family in the 1901 and 1911 censuses. The evidence concerns the son, Cyril (On a side note, I discovered he was injured in the D-Day landings (he was in the medical corps) - I love finding these interesting snippets).

I found the civil record of their marriage in 1899, but it's the church record that perplexes me. While the groom's parents' first names accurately reflect the birth record from 1875, the mother's surname is listed as Drummond, not the Devir in the birth record. It's not a transcription error, as it looks accurately transcribed from the register image. Could it possibly have been an error making the initial entry in the parish register itself? I can't find any possible Hugh O'Kelly/Anne Drummond births in Donegal that might be the groom's birth.

Hermy

Have you checked whether the mother was previously married?

Mollymoo19

Maybe also consider - a mother can sometimes go by her stepfather’s name.

p15574

I'll check both of those avenues, thanks.