tma98e320

So I have an interesting Abs/Bas/Asr story. I took it to the dealer last week to have a window part replaced, and $500 later the window was fixed, but they gave it back to me with the Abs-asr light array on (which had never come on until then). So my first question is could they have done something to make it come on? It seems like a pretty weird coincidence, and secondarily, what's the best game plan? I brought it back to the dealer and they looked at it and said my ABS are not working when the light is on and offered to put together an estimate, is that true?