Missing elements & clarification when calculating s_test

[fotinidelig]

Hello and thank you for the neat implementation!
In influence_function.py there are some things that aren't very clear to me in comparison to the paper.
First of all, here the computation for s_test is missing a multiplication imo. Shouldn't it be like this (?):

h_estimate = [ _v + ((1 - damp) * _h_e - _hv / scale)*_v
                      for _v, _h_e, _hv in zip(v, h_estimate, hv)]

according to this:

Furthermore, it is not obvious to me why in this func. you chose to apply grad() a second time after calculating the lement wise product. Is there a difference with running it two times beforehand?

Thank you and cheers!