I think it should be reported.  It's dangerous in my opinion.  If we don't report things like this we can't moan that the Board don't act.  If we do report it and they don't do anything, then I think we can moan LOUDLY.  This sort of work gives good gasfitters a bad name.  Hell, if a job is worth doing, it's worth doing properly.  Don't do shit like this and call yourself a tradesman.  It beggars belief.  Doesn't the owner wonder why the LPG people won't swap out the bottles?  Surely they want a safe job for themselves and their family?