Food Handling Observation: Why Touch All Food?

I'm quite lucky that I work at a place where there are a few good food outlets I can choose from.

One of my favourite is this kebab place where they make a mad kebab in a box, the only downside is the long wait time due to the amount of people ordering.

What's nice is that if the wait time is long, the shop will sometimes cut up a pide to place on the counter for the customers while they wait. Usually people just walk up grab a piece and leave, but today I saw this man who did something which upset me a bit.

He walked up to the pide and started to pick which one he wanted, which we all do as we want to get a decent piece, except he was picking with his hand.

He started off grabbing a piece, and looked at it before placing it back onto the plate, then he shuffled/pushed a few more piece away, picks up another piece then putting it back, he must have unnecessary touched 5 pieces before finally picked the one he wanted.

I may be over reacting a bit, but seeing all the people going after, unaware what he has done made me a bit upset.