Thanks to kim43235 for sharing this incident. We had a similar situation on a club ride earlier this week, but fortunately one of our rides noted to the rest of us "Be careful, this is a left/straight lane!"
Everyone signaled and there was no incident/issue with motorists but if we hadn't been paying attention it could have been a similar result to Kim's.
I also agree with the posts above about the importance of having a mirror. Mine is glasses mounted but whether it's handlebar, helmet or glasses mounted, a mirror is very helpful in many commuting situations.
Rick / OCRR