Douglas was happy that his side had created a succession of chances in the game at a soggy Sandhill Road, but was less enamoured by their inability to convert any of the try-scoring opportunities.
The coach said: “The conditions didn’t help but we created more than enough chances to win at Selby, we bombed quite a few chances.
“In the first half Selby were lucky to be level, on any other day we would have had 20 points on the board.”
Douglas added: “But when you take into consideration that it was the first time that this team had lined up on a pitch it was a decent performance I am just disappointed that we started the league season with a defeat.
“Selby were allowed to get away with a lot at the breakdown.
“They had two players yellow-carded and we had Mikey Readman red carded, but they were all correct decisions by the referee.”
Readman will now be sidelined until the Yorkshire RFU disciplinary board meet to decide upon the length of his suspension.
His coach said: “Hopefully Mikey will only get a small ban, he was red-carded for punching but he was receiving a lot of the same through the game.”
It was scoreless at the break at Sandhill Road despite Scarborough playing almost the entire period in the Selby half and the hosts receiving two yellow cards, but the failure to take advantage of this superiority came back to bite the Silver Royd team.
New YDO Graham Hogg gave the visitors the lead early in the second half with a close-range penalty but Selby hit straight back with a converted try.
Former Scotland sevens international Hogg added a further penalty to reduce the arrears and give Scarborough hope of a late win, but a red card for Readman for an alleged punch, sealed the visitors’ fate.