He…um…finished with Olaf, and put the toy back on the shelf, then moved on to a stuffed unicorn and repeated the process before police arrived.
This, as Josh Gad says on Twitter, is not the sort of warm hug that Olaf was likely looking for.
Apparently the violator of an innocent snowman grabbed the stuffed toy off the shelf, put it on the ground, and then proceeded to have his way with the doll.