I just thought I’d throw in some basic human psychology:
It is more likely that a person in an unusual or emotional situation is going to miss something than it is that a person who does pretty much the same thing all the time is going to leave something out.
Your priest, unless he is really new, has probably said the exact same thing, the exact same way, hundreds and hundreds of times. You on the other hand, are probably nervous and distracted by trying to be repentant and reviewing everything you said to make sure you got everything. It’s more likely that you missed it than that he did.
Now a complete aside…
Why don’t Catholics ever seem to write stuff down? I’ve read so many “I forgot” threads, it makes me wonder why they don’t take a couple of moments to review, jot down a couple of notes, and then pray to God saying, “Please help me to remember if there is anything else I should have on this list.”
One other thought, is God so petty that he would not forgive someone who forgot to mention something even though they clearly wanted to repent for doing it? Or hold someone else’s mistake against you?