Well technically the only way to PROVE it would be for you to know the guy. Anyone can claim to be right handed and produce pictures or video of them playing left handed when in fact they are left handed. Whose to say otherwise unless you know them. Or unless they clearly illustrate it by showing off on stage which, as a tribute band, I can't see him doing - there would be no point cos it wouldn't be what the real Jimmy would do.

I'll try and find the band on google anyway - I only stumbled across it accidentally once when browsing so I can't promise I'll be able to turn it up again but I'll try.