Pedaling 90 degrees OOP there is always a power stroke (and no stalling effect) and that *could* have prevented a FDGB moment.
We've all had a few of those technicolor bruises!
Had one from right buttocks all the way up middle of the back after an altercation with a drunk driver and my single bike (he had his license suspended for 90 days + a citiation). Took photos of it and had a heck of a hassle with the drivers insurance. Went through several adjustors in one year's time and had one tell me ". . . and you never really got hurt" . . . showed him the colored photo of my naked backside.
Amazingly, after a FDGB moment it is usually better to keep riding (if there are no apparent serious injuries).
As you say: lesson learned.
Pedal on TWOgether!
Rudy and Kay/zonatandem