Summer signings Craig Westcarr and Ben Davies put the Magpies 2-0 up but Mark Ellis halved the deficit just before the break to give Torquay hope and Tim Sills struck 13 minutes from time to ensure a share of the points.
"I thought it was a harsh free-kick against Ben Davies, the lad hit it straight at him from about a yard," said McParland. "But at the end of the day we should have defended it better. If you're not switched on and don't mark you get punished and their lad (Ellis) stuck it in from in our six-yard box.
"They were never going to score from open play but they caused us problems from set-pieces. I'm very disappointed but if you give bad goals away like we did, you get punished. We've got to dust ourselves down and get on with it."
The Scot added: "We should have been out of sight before they scored their first goal as we had a lot of chances. But everybody has to remember how good a team we are, how we played in the first half. The football was brilliant.
"It's disappointing because I wanted us to put a show on for the cameras and we only did half a job."