You can estimate who dropped the hand based on the cloth, since it's a colour only two people can legally wear, and only one was on premise.

You can't technically* guesstimate who the hand belongs to, because Narula still has both of his own.

It is safe at this time to deduce that this hand was with Narula, given the cloth, but it is not a severed hand of his body!


*the truth is, the other party members will help you identify the owner, because they've been picking up various limbs throughout the journey, and it's the same, er, culprit.