Good catch. There's a right and wrong way to swim backwards. The bad one is on your back looking for your buddy oblivious to where you're going. Instructors and guides do it all the time to keep track of their flock while leading.I am guessing you are meaning something different than I am thinking?
Before I started teaching, I never swam backwards in open water. I do it a fair amount in caves and wrecks.
I'll change it to "turning around vertically to look for your buddy". Cavers just dip their heads down to look between their fins or do a helicopter turn.