When the CV cover is ripped the CV joint can be damaged by water, etc, and subsequently fail.

If they damaged the CV joint when they did the repair, or left something loose, or the new boot caused a failure, you would have a case. If they simply replaced the boot and the joint was already damaged, and then failed due to that existing damage, then you have little recourse. In that case the repair was not a good investment (and perhaps they should have checked the condition of the CV joint) but I don't see what you would claim back to them on.

It depends on the nature of the subsequent failure, not on the fact that the same part is involved.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue