Knock Out looks up, thankfully at someone whose voice is not one he recognizes; no zombie or known enemy here. Of course, this could be an unknown enemy, but the bot doesn't look particularly bright (or particularly fast, or armed with ranged weapons), so he's fairly confident he can make a clean getaway if he must.

He turns his buzzsaws off and puts them away, and answers, "I didn't know there was anyone around to share it with. Is this your deposit?"

Even if it is, Knock Out wastes no time in tucking the crystals he's already harvested away in his trunk; his tone is artfully bored, like it doesn't really matter to him whose deposit this is. (Besides, he can hardly take the whole vein with him; sport cars don't have much storage space.)