Probably grabbed the controls on the top where the PTT/IC switch sits, not intending to transmit outside in the heat of the moment. Such a similiar incident shortly after the YYZ accident will surely raise some eybrows in a certain agency.

Additional crosswind training in a certain training program, perhaps?

Not sure how much good that would do. I've always found the sims are pretty wonky when it comes to x-wind training.

Because he accidentally ham fisted the yoke mounted PTT switch when he abruptly took the controls.

Not unheard of to accidentally bump or hold certain PTTs during times of duress.

One of the captain’s PTTs is designed as a thumb switch on the left side of the yoke. It’s easy to accidentally hold it down while white knuckling the controls.