Broken facial bones => bleeding into the nasal cavity => trickles down the throat, swallowed by reflex. I once had a tooth extracted that just would NOT stop bleeding - not a lot just a trickle. But it meant I was spitting blood every few minutes. That's fine when you're awake but, as I discovered, once you fall asleep you start swallowing the stuff. After about 30 minutes I woke up and projectile vomited half digested blood everywhere. This guy must have been vomiting faster than that because the blood looks quite fresh - leave it in your gut a bit longer and it looks like coffee grounds when it comes up. P.S. If you ever do vomit 'coffee grounds' and you don't have a good cause for knowing where the blood is coming from - like you've swallowed blood from a nose bleed etc. - call for one of Tom's taxis ASAP.