The winger created Niall McGinn's opener and was a constant menace throughout a 2-0 success which made it 12 straight games unbeaten for the Dons.
But Brown said: "He was a bit under the weather, it was touch and go whether we started him.
"It was snowing up here, and he lost his wallet in the garden. He and his father spent four hours crawling around in the snow searching for it. He got badly chilled and came in this morning like a wreck.
"The snow had melted overnight and the first thing he saw when he went out the door in the morning was his wallet! He looked like he was suffering from hypothermia, but he had a very good first half."
Of his side's good run the manager said: "I don't count, because as soon as you start counting, you falter in the next one. Last season we had 13, so that might be a target."