Combined HotWheelsKid's grenade launcher strat with my railing hop as I was sure that was much more clean movement.

I was hoping for a lower 5 than this, maybe even sub-5, but I'm not really convinced the grenade launcher alone can do it. I messed around with using the Hothead and Firefly first, and even tried destroying the explosives to the left of Martinez, but if any of that works, it feels like it's either slow or it kills him quickly on a fluke. Maybe something will come up in the future.

(Xbox 360 disc played on Xbox One S)