Well, you know if you confront him, he will lie even more. THEN he will get VERY angry, therefore increasing the distance between you and him even MORE, as your argument will feed his justification for what he's doing...and he will perceive it as "control" and run farther away from you.
So, just listen to what he has to say, and remember his reality is altered, much different from your own.
I'd always heard children that didn't feel "safe" told lies...now, also remember that the MLC'er is childlike in actions..and that includes lying because they are afraid they will "get in trouble".
We all want to set them straight, but in MLC that is not possible. He is insane, you are sane...sometimes you feel the opposite; been there done that.
Just listen and sort the garbage..the truth is always in there, somewhere.
I did ALOT of listening to things I KNEW weren't true, but listened anyway, understanding that right or wrong, he had a right to how he felt, just like I did.
I know it's hard to be just a friend to them, but try, anyway.
LA is right, you don't have to agree with what he says, just don't disagree verbally; you'll just start an argument you can't win if you do and make things MUCH worse than they are.
Again, remember this is reality as HE sees it in his current state of mind.
You'll also learn something more about where he is from what he says if you just sit quietly and listen.
Keep us posted.
Remember, as each person is different, every MLC/Transition is different..what works for one may not work for another. Most of the time it is trial and error for ALL involved.