Nah. Mike could have crushed each and every "tip" that Angela provided to the team by saying she didn't follow procedure. You have to remember, every piece of information Angela got, she got illegally.
Angela never filed paper work or did anything thru proper channels, stuff like that will cause cases to be thrown out in court. Mike could have easily kept Lobos out of jail, that's why the twist of having him be dirty is stupid and doesn't help the story line.
I think people are assuming Mike's been on the payroll from the jump. I believe he was recently flipped sometime after Lobos' arrest.
For instance, how did the bloody card that Ghost left for Lobos make its way back to Ghost at Truth? Unless I'm missing a huge clue, I thought it was Mike or someone who had access to Lobos who delivered the message.