Realize that "clean, sanitized surfaces" is a VERY relative term in foodservice. Also more times food is handled, more chance of cross contamination. The gloves/hands that put that cheese back in the have supply may have just handled sausage/deli meats or underwashed tomatoes containing listeria, now your cheese had extra "flavor" potentially. More of a risk in scenarios where the food isn't then reheated above temp that kills bacteria.

Basically, ideal path is ingredients prepped in sealed/clean factory process, handled once from safe storage into your meal with clean gloves