Unlike you, I don't claim read other people's minds or say that I know their motivations based on insufficient evidence.
But...you did exactly that. You claimed to know what Foots meant by that comment. Maybe you're backpedaling now because after rereading it you've realized he meant it as a provocation. After all, there's no room for any other interpretation. I've never heard anyone use the phrase "You up for that?" in a way that wasn't some sort of invitation or challenge.