Author of the project. Yes this happened, not with birds but with dead mice... And I did not realise it until like a week or so, not a pleasant cleaning operation.
Yup she's done exactly that at times, not the "prop door open", but she dropped the prey right in front of the door, went away for a while, came back, picked up the prey and went inside... But I wouldn't say it was because of detailed scheming on her part, but luck rather :)
Another thing she has done is to learn to back out of the corridor as the door locks, and then wait a while, and try going back in all while having the prey in her mouth.
EDIT:
So all small things like that has led me to tweak the algorithms, and add some extra settings to be tweaked. I mean the backing out move she did several times like 6 times in a row... Some of those times she managed to get in.
So to remedy that I added some settings for extra timeouts so she cannot try again as quickly and so on :)
1. Drop the prey in front of door.
2. Door detects no prey.
3. Door opens.
4. Higgs props door open.
5. Higgs retrieve prey FTW!