While in flight from the scene of Beatty's murder, what thought occurred to Montag about Beatty?

When leaving the scene, Montag realized that Beatty wanted to die.

In the middle of the crying Montag knew it for the truth. Beatty had wanted to die. He had just stood there, not really trying to save himself, just stood there, joking, needling, thought Montag, and the thought was enough to stifle his sobbing and let him pause for air.