It is possible for someone to bleed from injury (doesn't sound like a period), and it's nobody's fault: it's just that a lot of trans men experience dysphoria about their genitals and that might prevent them from learning how to take better care of themselves during sex. In some men who are on testosterone, the lining of our reproductive organs can sometimes weaken, which makes it more prone to tearing during rough sex. This is especially true if you're one of those guys for whom testosterone has made it harder to get wet down there. A good lubricant can take care of that.
This happened to me last year, with a client who did not stop, so I want to thank you for being so sensitive towards your escort. It sounds like that's what happened to him, it's definitely no one's fault, and he'll probably be alright. You two will have to work out how rough you can get.
I'm happy to answer questions if you have any! When I'm not a gainfully employed hoe, I do a lot of activist work, including educating trans men on their sexual health. If you have a question, I probably have the answer.