Damage caused to a phone

I bought a mobile phone in a store, and during the purchase I also paid for a glass screen protector. The seller himself attached the protector to the device. The protector does not cover the entire surface of the screen (apparently it does not match the phone model precisely).

Yesterday the device fell, and the impact was at an angle that hit precisely the area of the screen that was not covered by the protector. As a result, the entire screen shattered, while the glass protector itself remained intact.

The question is: in such a case, does the seller bear halachic responsibility for the damage, and am I allowed to demand that he bear the cost of replacing the screen, since he is the one who sold and attached a protector that does not properly fit the device?

Shalom u’vracha 

It is not possible to obligate him to pay for the damage caused to the device, as this damage is a distant form of indirect causation (grama) stemming from the improper attachment. 

However, he can be required to compensate for the depreciation in the value of the phone (when it was still intact): the difference between the value of a phone without an adequate protector and the value of a phone with a properly fitting protector. 

Have an additional question on this topic or need clarification? Leave your comment below. (Please note that the comment will not be published but will be sent directly to the answering Rabbi for review and a private response)