Well, here's the panel of Kid talking about it (chapter #928):
There's another translation that says that the mentioned SC hurt one of his men and he repaid the favor, but I never saw a translation that suggested an amicable affair. He did injure one of BM's Sweet Commanders, whatever the reason.
Even if you consider that he might've staged the entire thing, this simply isn't how Kid acts. He didn't care about Caesar's weapons, he didn't back down against Kaido, even after being betrayed by his allies, he went head-on against Shanks, even after losing an arm in the first battle... Kid is reckless, I doubt he would make a deal for a poneglyph rubbing, especially considering that he can't read them (the only way of knowing that it was the real poneglyph is if you made the copy yourself).