Digitigrade Leg Stretching Problem

[Nymoo]

Heya

After a while of googling I've managed to figure out how to successfuly rig a seperate mesh to a custom avatar. However, I encountered a problem: 

http://gyazo.com/f85bdd1bb7154c38da0567f4a05caf75

About half of the raptor claw, on the foot, stretches dramatically, and it appears to follow the other foot/leg when walking.

This is how it looks like in Blender:

http://gyazo.com/0cc1f9378f52d4e0703dfd6490e12799

Perhaps it gets sliced down the Y axis? Perhaps the raptor claw is way out of the boundaries? I'd appreciate any help, thank you!

[Kwakkelde Kwak]

If the one toe is following the wrong foot, it means the toe is (partially) weighted to the wrong foot. If you used a "copy bone weights" command, it's probably caused by the legs not being far apart enough. Easiest way to solve it is to paint in the right weights by hand.