One of the questions on the test in Ontario is how often one should check the mirrors. I watched a national safety program on driving years ago and the suggestion was every 6 seconds. The answer for the driving test is 5-7 seconds. Your point SF, is an excellent reminder. It's likely more important at a stop light or stop sign.A drunk rear-ended me at a red light one time. I had the bike in gear and was holding the clutch lever in. The bike was knocked out from under me and my left hand was Ripped away from the bar/lever. Took a few months for my left hand to recover as I had a solid grip on the bar (holding lever in) when the bar was Ripped Out of my Hand.
Sometimes good to be sitting with bike in gear, sometimes not. Anything can happen.
YES. It was my fault... I did not re-check the mirrors soon enough so he got me.