Turns out this video of Justin Bieber roller skating could be exhibit A in a lawsuit, because TMZ has learned it was shot by the very same paparazzo who claims he can't work because Justin injured him.
It's like the handbook on how NOT to win a lawsuit, but Walter Lee shot the vid of JB rolling with Chris Brown Saturday. A total freakin' miracle since just 3 days prior Lee filed legal docs claiming he might be unable to work forever.
As TMZ first told you ... Lee (who goes by "Malack") filed the suit last Wednesday, claiming he sustained some nasty leg injuries when Bieber drove a Ferrari into him last year.
Lee might have a case for being rusty on the job -- he blew the money shot of Justin falling at the rink -- but more likely ... it's just the worst case of petard hoisting since Hamlet.