Yeah but time and material is a license to print money.
Anyways, you can't have an apprentice on a stop watch. So the kid works his arse off for 3 days knee deep in mud and snow and then you cut him off and send him home for the week with half a paycheck. Next week he will be working for someone else.
It sounds like a big job was done, in the future if you have big jobs done without quotes, you should periodically 'check in' with the contractor to see what the costs are getting to be.