Either way... I still don't think it was that big of a deal....
Another thing is that we never REALLY know how many films people have been in.... Recently you had Foster say she was in 20 other films that she wasn't credited for..... I actually had a person thank me for talking about their uncredited films
What's wrong with just saying exactly why you're writing to them?
"I loved you in Bambi."
Or, if that seems a little too...whatever for you:
"I'm sure you've done some impressive work, but honestly, I'm writing to you purely because I saw you in Bambi. Not to diminish your other work or anything, but I really liked you in Bambi."
If you've never seen him in anything else, why mention it? He knows he was in Bambi, you know he was in Bambi, you're writing because of Bambi, so just talk about Bambi.
From where I stand, you completely deserved that, what you refer to as an "unappreciative comment".