After he has killed all the Wildlings except Tormund and Yigritte, why would he run away? He defeated almost the entire Group. Plus Yigritte is clearly so in love with Jon that she would tackle Tormund together with him and Jon knows that. And to top it all: He has got 2 freackin' dire wolves whom he knows very well... so he could have easily finished Tormund with their help.
Why ride away? Why flee? He has got the upper Hand!!!
Is this just bad screenwriting or am I missing something?
As far as I remember from the books
Spoiler
he hardly killed half the Wildlings of the Group so that's why he ran away...