I spoke to the owner/pit crew chief the other day. He apologized for the outcome. Basically he said he took a chance and it didn't pan out.
He said that he thought it was going to rain again and that the race would be stopped. If the car was in first when that happened, he would win. So he waited and led for a lot of the race. The problem was it didn't rain. And everyone else pitted on a caution. Since he waited, he didn't get to pit on a yellow which would most likely have kept him in the lead or close to it. Since there is a mandatory pit stop that had to be taken before lap 90, he had to pit on green, That is why he lost a lot of spots. Plus, the right front tire had no tread left on it. He also admitted that he should have changed tires but he knew if he had they would have finished even worse.