He would have been coughing up blood from that wound to the chest, internal injury. Lungs could have nicked. That blood is going to start come up. Both the coroner at trial and several coroners on TV have talked about the blood in the sink. I think she could have been stabbing in the back at the sink, reaching around chest area to stab more, stabbing back of the head.
Travis standing at the sink, holding on...rapid stabbing to the back in frenzied, tight pattern to the back...think about hunching at the sink. Slice/stab, slice/stab, etc. Self-defense?