Mark Munoz came into UFC 138 ranked #4 in the world at middleweight in the USA TODAY / MMA Nation Consensus Rankings and did nothing to lower his ranking with a resounding drubbing of #12 Chris Leben. Following his win, Munoz made it known that he wanted a shot at UFC champ Anderson Silva.
Munoz has trained at Black House several times, increasing his own skills as well as providing men like Silva with a top shelf wrestler to train with. Silva was told by SporTV about the challenge from Munoz and didn't seem too thrilled (translation by Tom Mendes):
I hadn't even seen that (Munoz's challenge). I thought Munoz was a friend, but that's okay...
The Black House camp is one of many in MMA that does not believe in fighting teammates and it seems that Silva thought that Munoz's time in the camp was enough to make him a teammate.
Mark is making the right career move though, there just aren't enough big fights at 185 for him to stay in a holding pattern until Silva retires or leaves the division. Munoz was not disrespectful to Silva, merely vocal about wanting a chance to be the best in the world.