Dimitri Borisov did not take a picture of an avalanche in the vicinity of the tent. He took a picture of an avalanche nearly two miles away, where avalanches do take place and where conditions are very different from the area around the tent. Dr. Vladimir Borzenko proved this by going there and taking pictures of the terrain himself.
This photo was taken from the top of Boot Rock of the area where the avalanche was caught on camera:
This photo is the best place to see evidence of an avalanche:
And this photo was taken from where the tent was located:
Using that patch of snow or ice or whatever that is as a reference point, it’s very obvious that there was quite a bit of distance between the two locations.
As for whether avalanches are possible at the tent location, I defer to Dr. Vladimir Borzenkov. There is no record that an avalanche ever took place there. But even proponents of the avalanche theory have had to admit that the slope just isn’t steep enough for an avalanche to occur there without human intervention. Furthermore, if one did occur there, it wouldn’t be a big one or go much past the side of the tent facing the forest line. Again, the slope is just not steep enough for it to go any farther. In addition, it would have obliterated the footprints. And it had to have missed the entrance since the entrance was still in an upright position when searchers found the tent a few weeks later.