There is a strong history of the public narrative being "steered" by the opinions, and understandable plethora emotions, that family and friends were going through when Brian went missing. For example, for a long time we thought that Brian made glowing grades in medical school, but later found out that he was just doing okay. The whole thing about how he was going to propose to Alexis in Miami (a point that was reiterated so many times) seems to be pretty much unfounded. I could name a few more examples but basically, anything that those close to Brian really wanted to be true, was presented as fact.
I think the narrative about Clint and Brian's friendship may have been skewed for similar reasons. It's no secret that Clint fell way out of favour with a lot of people, due to him seeking legal counsel and subsequently refusing a polygraph, or any other further cooperation. So now we hear a lot about them not being such good friends... they squabbled a bit... they weren't that close etc... Meanwhile, it sounds like in reality Brian and Clint had a colourful history of partying together, there's pictures of them looking like they're best buds having a ball, Clint was one of the most recent people to post on Brian's Myspace page (having a dig at him, frat bro style), Brian pushed himself to go out and party with Clint that night even though he was tired. They were friends, and there could have been a whole lot of loyalty in that friendship. Everything that gets pointed out as evidence to the contrary... absence of phone calls for weeks, the odd falling out, one not getting along with the other's girlfriend, figuring out that they're not suited to actually be roommates etc... all sounds consistent with the ups and downs of friendships during college life to me.
When it comes to Clint and Brian, it's hard to know what is relevant, what is true, and what has been blown out of proportion.