League president could of solved this complaint without getting you involved by just telling the complainant lane had to be oiled to be certified.
The lanes didn't have to be oiled to be certified, being a certified house they already are certified for league play.
While the the L.Pres. could have just told the complainant that to placate them, it could cause problems later on.
Because if teams have to move or had had to move in the past and the lanes aren't oiled or had not been oiled in the past.
People could complain that those games don't count because they were on uncertified lanes, because the L.Pres. said the lanes had to be oiled to be certified.
In the OP's situation nothing was particularly done wrong.
The OP's team and their opponent made a request and it was granted. If the L.Pres. had a problem with it, he should take it up with whoever granted the request.
As for the person that complained, while they might not like it. It has no bearing on the conditions that they (the complainer) are playing.
Because as long as the two teams (playing head to head) are bowling on the same pair, it doesn't matter if they are used or not or what the conditions on the other lanes are it's considered fair competition.
Look at this way, if the lanes hadn't been oiled and they proceeded to shoot 300's or 800's someone would probably complain about how they should have been oiled like the league lanes were..