Thanks to that knocked over trash can, the wolf only gets halfway through the bowling alley door before in swings closed. He has to decide whether to try to squeeze forward or backward. And since that trashcan just inside is blocking his way forward, the easiest plan is to back the rest of the way back outside. The wolf may have four paws, but in this form, he doesn't work doors very well. Martha was smart to get inside.
Once he's wiggled his way back out, he stalks back and forth outside on the steps to the bowling alley for a few brief moments before turning away to find something new to hunt.