I taught 8th grade math... however, my Contracts Law professor has repeatedly stated that breaching contracts is not a criminal act. It happens all the time. As long as you pay non-breaching party for the loss they incurred (or the expected profit that you suddenly denied them), there is no crime.
Two private parties signing a contract does not create a new law whose violation qualifies as an "illegal" act.
wasn't that the issue, that the plaintif wasn't paid what he was owed when the contract was breached?