Gaige is a liar and wants his payday.
Having said that, I've seen both defense and prosecution witnesses become incredibly hostile and unable to agree on even simple facts with the person cross examining them... Gaige only seemed to object to the term "chase" and basically buckled as soon as he was questioned further about whether Kyle only shot after Gaige pointed the pistol at Kyle.
If he'd just argued anything, like he didn't think the gun was pointed directly at Kyle, there's a chance the jury would buy it, or at least take it into account. And juries are really fucking dumb.
While I hated his oily poor boy ow my arm narrative on direct questioning, at least he saved us a bunch of time by admitting Kyle had a pretty good reason to vaporize his arm.
I don't think there's enough time in the world for Binger to come up with a redirect question to dig them out of this hole.