I have a friend whose wife was not honest with him, now he finds out she cannot get a visa. This has met another girl and has grown feelings for her. Would he have difficulties if he divorced his now current wife, and tried to petition the new girl on a fiance visa? He should not have to suffer because his current wife lied to him.

Your question is about K-1 so why post this to the K-3 forum?

I dont see any problem other than the IMBRA rule on multiple visa petitions within a 2 year period, if he has a petition filed and denied for current wife, he may have to file a waiver of that IMBRA rule for the K-1 petetion.