Wala pa naman yatang 5 minutes sa sahig.
Seriously, this needs to be addressed by management. But you can't blame the poor overworked underpaid employees. I don't know what their policies are, but I believe dropping products on the floor has severe repercussions on their employment or on their performance rating.
The employees were trying to save their skin, but somebody saw them.
This could be happening elsewhere and we won't even know. Your burger could have flipped down to the floor, and it tastes good.