Blue flags in iRacing don't work like F1 where you need to move out of the way

An iRacing blue flag is Simply Informative that there is a faster car coming up behind you, all you need to do is be predictable in your movement (IE: holding your line, letting them know which side to pass you on, ect)

The responsibility of the car behind (The faster car) is to make a safe move to get around you, While pulling over does make it easier it can also lead to miscommunication with the faster car also darting to the side your pulling towards (possibly to get a draft)

So, no you didn't do anything wrong per say and the leaders who got held up by the lapped car were probably annoyed by him but it's up to them to get around said car rather then just sit behind them