I wouldn't blame SIL for this. If your wife said "We don't want dogs here.", then yeah, he'd be a real clod to bring it anyway. But she talked to him and he said "Don't worry, I'll clean up, I'll do this, I'll do that" and I have to assume she said OK at the end of that conversation instead of a nice, firm "The answer is NO."
You get alone well enough with SIL you said...so call him up and say "Look SIL, I'm sorry, but I really don't want the dog here. I know you said you'd take care of any problems, but I just don't want her here at all."