This just makes sense. They most likely did a repair or something underneath the bricks. To do this they took them all out and put them in a big pile, did the work and then started to put them back.

Now are you going to just put the bricks back quick and efficiently since all the bricks are the same, or are you going to inspect nearly every single brick with a line to ensure you are placing the correct brick in place?

I know what I would do.