I respect that with the power of language, we don't necessarily need to capitalise anything, because a description of how a character is speaking is more powerful.
Take my example:
The hooded man took another hard right through a thin gap between two stalls, forcing Rett to speed up again. With the man out of sight, he sped up, half in desperation, half in fear of losing him permanently.
“Watch it!” a man cried as Rett pushed him out of his way.
He bumped into a woman as he shoved past, spilling the contents of her bag onto the ground.
"Sorry, ma’am!” Rett shouted back, without stopping to help. He wove his way through and between more shoppers, and quickly took the same right turn that the man did. He ground to a halt when he realised that the man was gone.
His breathing quickened. “DAMN it!”
I've already got Rett shouting back toward the woman after spilling her bag, but his final words are a curse. A different type of shouting; a real exclamation.
What should I do? Is capitalising here okay, or should I return it to normal case and give explanation?