He did lose one of his prized clients to Lou. I remember reading Marty's book where he said Lupien suggested that Marty should demand to be one of the top five highest paid goaltenders and that he should demand a trade if it meant that. Also I remember that Lou refused to work with him and they haven't worked with Lupien client since or at least until Gelinas apparently.
Fortunately for Marty he was old and mature enough to realize that he was better off moving on from this guy as it would only hurt him
I'm not sure I can say the same for Gelinas who is barely legal to drink and might have his head clouded by this guy
For an agent that's been around for a while, this is amatuer hour
It's about the player and getting him a contract not your ego and quest to get a few extra bucks out of a guy with more power than you'll ever see in your life
A quote like that would only fuel Lou more to stand his ground, that is something you never admit to somebody you are trying to negotiate with - this agent just lost right there with that admission