Grayson said: "The most disappointing thing was the way we started the game and it certainly wasn't the best result we could have had.
"We were still in the dressing room for the first five, 10, 15 minutes and we didn't play to the conditions as well as we should have done.
"It was a very difficult pitch and we wanted to play as if it was a normal, dry pitch. We had to play the percentage football and we didn't do that.
"Credit to Exeter because they did. They worked us a lot harder in the first half, we responded in the second half and had a decent go at them. On another day we might have got something. There was a full house looking for an upset and that is what happened."