I have personal experience with "weather delay" from AC Jazz. Two years ago, I was booked on a flight from Milwaukee to Toronto. The flight kept on getting delayed further and further. They're excuse was "weather in Toronto". Seeing as I have my commercial pilots license, I called up my aviation weather reports and there was barely a cloud around Toronto or on the way to Milwaukee. After finally pressing the issue, I was told it was actually due to mechanical issues and that the aircraft would be further delayed. I finally got a text on my phone that said it was cancelled. I told them that I needed to get back to Toronto and was heading in a rental car down to Chicago to get the last flight out of there, and had they been honest with me in the beginning, I could have made alternative arrangements earlier. They finally agreed to put me on a United flight to get back, and a month later I had an appology letter from Jazz and 10,000 points too. ^ How's that for service...I was impressed!

That being said, you never know what the situation is. I don't know what the weather was the day your son travelled, and it could have been the case, but I've seen both sides of this situation...