Dropping food while eating it and holding mouse button still causes something weird because the eating animation stops after amount of time when it should be eaten, but the crumbs animation stops after five seconds and only then hunger and health points are added.
To me, how it should look like is dropping food while eating it and after that starting eating another one without any delays (I guess eating and falling crumbs animations should be somehow connected).

Update (1.9 Pre-Release 1):
Dropping food while eating it makes it bugged and thereby it can't be eaten any more (while holding right mouse button animation of 'first bite' keeps repeating).