Something similar happened with me in the past. My wBF and I both went out separately with friends for a night, and we agreed to meet at my place at 11 PM to stay the night together. I got home at 11 PM, and he hadn't left his friends' house yet (an hour drive). I was pissed.
Everything that happens now matters. He asked for a chance to prove himself to you. He failed that opportunity. He should have showed up earlier than what he told you. I don't think you're overreacting.