No real hard evidence of this. I'm pretty sure Vito and Mike both knew it but wouldn't or couldn't act on getting revenge. Mike's "death stare" at Carlo was the look that he now had to act on it. He was hesitant to do so because it meant killing his sister's husband (something Vito couldn't bring himself to do). Mike HAD to hear Carlo confess it before ordering Carlo be killed. He HAD to be sure beyond any doubt. (Mike had to wait until Vito died so Vito couldn't be responsible for any of it).

Again, there is no definite proof of all this; just my own beliefs after watching the movie a few hundred times.