Some peds just have a restwish

Just had my car M.O.T. done It's an old car so invariably there were a couple of things needed doing . . . one of which was a couple of new break pipes on the rear brakes.. However they weren't properly connected and were leaking as I found the first time I tried to brake. Anyway I took it straight back and the problem was fixed immediately (well after about half an hour or so) So off I depart again and a short while later I happily driving along at 30-35mph . Ahead of me waiting to cross is a woman with a baby in a buggy.. she turns looks at me .....couldn't miss as I have a big red car... and when I am about 40 yards away she pushes the buggy out and strolls across the road, causing be to firmly apply my newly fixed brakes. OK it wasn't quiet an emergency stop but if I had just left the M.O.T place after the first time when my brakes weren't exactly at full efficiency I think it might have been a very close thing. Which leads me to another question.....Say I had just left the M.O.T. place after they had f***ed my brakes up... and I had hit this woman because when I tried to brake they didn't work... who would be at fault......Me, do I have a responsibility to check that everything is in working order before accepting my car back.....The M.O.T. place for handing me a defective car (with M.O.T. certificate). . . .or would we share the blame