Lyric discussion by retro1986 

Cover art for No Hero lyrics by Offspring, The

'Johnny's strange behavior was a tip-off,' they say

Sounds like people are blaming the narrator for Johnny's suicide. As if the narrator murdered him. But it was Johnny's decision - the blame is being misplaced. Also, perhaps the narrator is blaming himself, and it doesn't help when other people reinforce this misguided belief. It's not the narrator's fault.