It's relevant because it is nearly 100% the cause of the fight.
There are only a few situations which would invoke a fight or flight response from someone, and revealing/pointing a gun at someone is one of those situations.
Given the circumstances of the night, can you think of anything reasonable that would cause the two to fight? They both did not knew each other so there is nothing in their releationship that would cause them to fight (other than racism). Random strangers do not just start fighting each other.
And if the gun wasn't revealed prior to the fight, how exactly did it become free and unholstered? Zimmerman claims that Travyon tried going after the gun when it was on the ground. Guns don't easily come free from a holster, I don't think it can come free that easily during a fist fight.
The prosecution should really dig deeper into the cause of the altercation, and bring in the holster as evidence.
Who claimed the gun was on the ground? I don't remember that at all from any testimony or statements.
You can't reason through people's reactions like that. Someone acted unreasonably or none of this would have happened.
I may not have the clearest understanding of the law, but if I'm following you correctly, you're saying that Trayvon had no legally justifiable reason to to be afraid simply because he didn't know of the existence of the gun?
Of course I'm not. I'm saying you can't cite something as justification for that fear if he didn't know about it.