Jamestser did that today in practice. Crazy!
I did it in a match a long time ago. It was on a serve return. I was completely fooled thinking he was going to hit it to my forehand, I leaned in that direction, and it went to the backhand instead.
The guy was so shocked he didn't even play it.
that's crazy, i have been trying to do it when i was playing and i haven't yet successfully done it.
It's not a shot I would recommend for matchplay.... I mean I only did it because I was badly fooled and just stabbed my racquet back in despiration. The result was a moon ball that would have been killed had my opponent not been so stunned.
In practice I could hit a reasonably paced shot behind the back (may just try and see if I can still hit it

), but other than the scenario I found myself in, I see no reason to hit a shot like that in a match.