This is one of those times when better punctuation would actually do a lot to improve the story. "It was raining poetic justice, Crowley thought," means "Crowley thought that poetic justice was falling from the sky like rain."
"It was raining, poetic justice, Crowley thought," means "It was raining, which Crowley thought to be poetic justice." Also I'm pretty sure "fitting" would be a better expression than "poetic justice."
So he had a smiling contest with a Wall-Mart greeter or something?