Hey everyone - I brought my Dodge Sprinter to get inspected recently and the mechanic said it needed it's ball joints fixed. They took care of that and ever since I got it back from the shop the ABS kicks in whenever I break hard. The shop took another look and are saying that the computer that handles ABS breaking is bad and it's a totally unrelated issue to what they did. They are also telling me that it isn't a problem that the ABS now kicks in constantly and I don't have to worry about it.

My questions are
1. It seems like they probably damaged the ABS sensor while doing the ball joints. I'm not a mechanic, but what do you all think? It feels like they're lying to me in saying that it's an unrelated issue to the work they did.
2. It definitely seems like it isn't good that the breaks wont stop hard anymore and start doing the ABS fluttering all the time, this isn't safe, correct?

Thanks for any help or advice