County took the lead after 17 minutes through Richard Butcher before Moses Ashikodi equalised from close range following a goalmouth scramble.
Shrewsbury striker Grant Holt scored from the spot after Delroy Facey pulled him down in the box before Graham Coughlan extended Town's advantage. But Jonathan Forte's late strike ensured a nervy finish.
"We could easily have had three or four before we did score," said McParland. "And then we gave away a stupid free-kick near the corner flag to give them an equaliser."
On being sent to the stands, McParland added: "I questioned the referee's decision not to book Shane Cansdell-Sherriff for two blatant fouls on Myles Weston even though he had quite rightly booked Jamie Clapham.
"There was no bad language, just a question but I got sent to the stand. The trouble is, and other managers are saying this, we have boys refereeing a man's game."