The question is what went first -the bracket or the bolt -or wasnt the bolt tight enough hence putting excess load on the other mounting-either way its a
problem.
That bracket looks like a straight shear failure-through manufacturing defect.
Its my job to come to conclusions after breakages like this in the engineering field and all I can say from the pictures is that the the bolt sheared right at the point of mounting ie something twisted it straight off.
I personally think the bolt went after the bracket.Its a clean break on the bolt caused by an imense amount of force twisting it off-Ie the caliper rotating on the disc at those speeds
The bracket break is not clean -consistant with material failure-
All this is only my opinion, and experience gianed by over 25 years of being in engineering and dealing with similar occurences.
Draw your own conclusions-but this is a serious matter and someone could have been killed -even worse an inocent party.
So make sure you are dealing with reputable companies-Research and Developement costs money - anybody can CNC up a couple of brackets but unless they have been designed to take the forces generated in your brake system and made of the correct material with the correct shear properties to take the loads, you are putting your life (and somebody else's life in their hands
Its about time this country went the same way as Germany and you can only fit approved kit to your cars
