With the second graph, Turbo mode often gets up to 60% or 70% confidence before detecting an issue. That seems odd, since I'd expect most edges in a graph to be colorable and only a few to have issues, so I'd "expect" most graphs to look fine up to that level. Is this an issue with the confidence equation and prior, or is it just expected that nobody would stop until they hit 99%+ confidence?
In other words, perhaps I'm just asking for the answer to Exercise 2!