A sound suggesting an approaching avalanche could lead to the panic you mention. Plus, someone further up mentions the possibility of the tent door being frozen or difficult to open.
I think it's suggested that some might have taken clothes from those that froze to death, explaining those left naked. If some climbed trees and fell, or fell into a ravine, that could explain most of the injuries.
The hikers are awoken by some disturbance. They discuss among themselves briefly, and decide to go out--a few people start putting on shoes, while someone is attempting to open the tent door. Something spooks them, and they all panic and want out now. A convenient knife to the wall provides a faster exit point, and they run out and make for shelter of trees.
I have some experience hiking and backpacking, but the information given in the Wikipedia article is way too sparse for me to attempt to derive a coherent explanation. For example, there's no indication of where the clothing was located for those who were undressed; more importantly, there's insufficient explanation to posit when the group broke into the two who stayed at the tree, the three who tried to return, and the four who died in the ravine.