Apparently it was much worse than that, not that I agree with the firing. I am disappointed to find out that Camby and Wallace were both part of the problem.
From the Oregonian's John Canzone:
Nate McMillan probably won't ever expose which of the Trail Blazers he wanted gone from his toxic locker room. But he told me in a pregame chat 12 days ago that he looked down his bench during a recent game and saw Marcus Camby, legs crossed, arms folded, sitting back in his chair with a "What are you going to do, sucker, bench me?" expression.
McMillan was ticked about it. And grumbling too about what he perceived to be a faction of passive-aggressive players who were undermining him as the season spiraled out of control. He said he was doing what he could (film sessions, pep talks, holding back minutes) trying to get control of things.
Same night, I spoke to a veteran player who believed Camby and Raymond Felton were trying to get McMillan fired. I later learned that Felton's off-court sidekick, Gerald Wallace, could also be back-biting and subversive.
Makes me miss Brandon Roy that much more.