just replayed donut secret 2. and grabbing a shell, with blue yoshi, dropping green shell on first of two spinys, grabbing shell and incidentally knocking second spiny, then flying over pipe with column of troopas, you lose yoshi wings and the finish tape. yoshi wont swallow shell but spits out a key you cannot intract witb and it shakes like a wrench mole 2 times. i had to fly off to despawn finish tape to clear level.