RIV is pretty much one office in Toronto to push the paperwork. The real work is done by the approved mechanics who modify and inspect the vehicles then send in a check list saying that it meets all the requirements set out by RIV.
That's sort of the joke - the RIV instructions say to put the km/h stickers on the speedo, and put on French language air bag and seatbelt stuff (wacky Canadians) - the dealers typically laugh and will do it if the client really wants and either way check off to say that they did... The big items are DRL and child seat restraint hooks.
I agree with the last post, let him buy it first then he can pick it up and drive it through the border. Or if you can get to him and then sell it for CASH, then it's again his problem to get it approved or he'll have to sell it to an American i it has to go back to the US.
Cheers.