B says Z was lying about yelling for help, then having his mouth covered by TM. Could not be covered and yelling, along with alleged lack of blood on TM hands.
It's simple. The struggle went on for about 40 seconds. At one point Z's starts yelling, then has his mouth likely covered as he claims. Then some seconds later, Z starts yelling again, after TM hands moved. TM had allegedly noticed Z had gun. goes for gun. Z starts screaming for help while's he's struggling to keep TM's hands away from gun.
No blood on TM's hands because Z wasn't bleeding enough to have blood drain out of nose? Blood only drains out of nose once Z upright for some time?
I've made that observation many times. When he was on his back, the blood was running UP his nose.