EEDSL I think your copilot is to be commended. Offshore flying is very routine and it is easy for complacency to drift in. Perhaps in that instance there was only one other deck in the vicinity, but in other occasions there may be several. It is all to easy to see an installation, talk to it, and thus be convinced it is the right one to land on, when in fact it is not. The only way out of this trap is to ALWAYS put the next destination in the GPS. It should be mandatory in you SOPs (it certainly is in Bristow) but if not, it is only a matter of time before you land on the wrong deck.
Personally I have taken off from the BraeA, early morning (never my strong point) turned left and pointed it at the next destination (BraeB) only to notice shortly afterwards that the GPS was pointing at something completely different. Yes, I was pointing at the Miller. Oops, but it happens. A good pilot (and good SOPs) does not rely on him being perfect, rather he builds in safeguards (error tolerance, if you like) so that one error doesn't become a catastrophe.
As I said, you should be thanking your cojoe not slagging him off for doing his job properly. If you had insufficient fuel to do the job properly without cutting corners, that was your fault.