What if you don't get any answer ? Shall you go on ? Leave unexpectedly? Apparently his staying on the job for his hourly rate wasn't an issue and was even expected.
It won't always work out like it did for OP, so it really depends on how much risk you're willing to take. $18k probably isn't enough to be worth a lengthy lawsuit over, so a more aggressive client might've cost OP significant unpaid time. For some, that's an acceptable risk. For others, not.
