To be fair, Thomas, she effectively went through a red light (right over both her stop line and the advanced one), and then blamed having been on nights - you picked her up on that too. We're all laughing because we assume that as you are 'one of us', your Mum is probably a good sort at heart, but any copper following and seeing that red light jumping and hearing "I've been on nights" as an excuse probably wouldn't find it all that amusing.
It's a fine line, and sometimes luck, between an amusing family anedote, and someone being killed, so I can understand people being sensitive about it. If someone had been relying on the lights and crossing that road, a moment of inattention could have ended in a funeral.
I think anyone who drives, me included, has moments when they think 'oops, that was close/stupid', so I'm not trying to be superior here, just seeing both sides.