“If you were sorry you wouldn’t have done it to begin with” has also come up on several occasions in my personal life. Haven’t figured out how best to respond to that one.
I'd say no.
Your thesis needs work IMO.
Make sure you don't fail morally by ever presenting an incomplete/unsound thesis again!
(Serious question)
What about responding to that honest emotional expression directly? "Ouch. I hadn't realize how much I'd hurt you. Truly, I'm sorry."
By that argument regret seems impossible. Some nuance is probably lost here, to be fair.
In each case though you did it to begin with because
1) while you knew you would be sorry, you surmised you would be more sorry not doing it, or
2) did not believe anyone would mind your actions, or
3) did not realize you would so much regret it when others took offense to your actions.
#3 absolves you of nothing. #2 absolves you unless you thought they wouldn't mind simply because they wouldn't know. #1 could absolves you in theory, but might just reflect priorities that the recipient of your apology doesn't share.
All this is likely of little use to anyone, but I couldn't resist writing it down anyway.
We (humans) are not always good at predicting the future or other people’s reactions. We do stupid things and make stupid mistakes all the time and when these things affect others we often feel sorry that we did those things.