John Connor: I knew it. I knew it was coming. But this is not the future my mother warned me about. And in this future, I don't know if we can win this war. This is John Connor.
This is right after Conner jumps down to the lower level to get to the grenade launcher and hurts his shoulder. He is crawling away from the T-800 and the shot is from right behind Conner's head. The T-800 is practically right on top of John, but when he shoots the oven and the molten steel lands on the T-800, the shot shows John like 30 feet away.
Reese's introduction isn't the only thing that stays the same about the character between movies. Here he uses his preferred weapon - a sawed-off shotgun. Marcus isn't keen on having a gun aimed at him though, so he snatches it out of Reese's hands, then teaches him a trick to keep that from happening - fashioning a safety strap. Reese puts that same trick to use after he steals a police shotgun in The Terminator.