If you're referring to the Warren Zanes biography on TP, it is excellent. Campbell's is better, given to the first person accounting of the events.
Another key part about the whole Boys of Summer incident, Campbell had pulled up to TP's house one morning expecting to have their usual recording work session. Tom was loading his guitar and bass into his car. Campbell asked where he was going and Tom kinda sheepishly told him he was off to do a session w/ Dave Stewart. Campbell deftly explains his passive aggressive response to Tom sneaking off behind the rest of the band's back to record with someone else. Tom kept EXTREMELY tight control over what members of the band could do--particularly Benmont and Stan--so the hypocrisy wasn't lost on Mike.
All in all, Tom being too disconnected (or coked up; they were all heavy into their drug days) to hear the potential of Boys was probably the best for everyone. Henley wrote an all timer. Campbell knew he could write great songs for other people. And Tom would have to come to the terms with the fact that as much as he liked to control tense band situations by asserting simply "I'm Tom Petty," Mike Campbell was indeed Mike Fuckin' Campbell.