No I get that bit his point was that before A11 lovel the backup commander hadn't flown on the LLRV and LLTV so if Armstrong had gotten ill and Lovel had needed to command he wouldn't have had any experience flying. did lovel train on the vehicles before A11 launched
He definitely trained with Armstrong in the helicopter training that was a precursor to LTTV training. I don't know about his training in the LTTV.
Again though, your acquaintance is trying to build a strawman argument. Lets rewrite history and assume that Armstrong got sick and the backup crew had to fly. No LTTV training would not have precluded Lovell from commanding. That may or may not have hindered the landing. If he failed, then A12 would have attempted it, just as they would if Armstrong had failed. So what is his point, assuming that he has one?
Hoaxies tend to forget that each and every flight was a test flight. If the landing on 11 failed then the challenge would pass onto the next and so on. The only thing that might have stopped it would have been the astronauts dying in the attempt and even then I'm not so sure.