Central defender Tom Parkes’ angled strike cancelled out a thumping 30-yard, 35th-minute opener from Plymouth playmaker Conor Hourihane.
McGhee said: “Tom is an unlikely goalscorer but he is a terrific footballer. He’s got great quality in his feet, particularly in his left foot, so it was no surprise to me that he finished the way he did.
“As I came into the dressing room I heard a few of the players talking. I think it was Lee Brown’s voice I heard saying ‘come on lads this gives us something to build on’ and I hope it is.
“I was very pleased with the second half but I was very disappointed with the first half and the goal we lost. But we have got a lot of work to do on Saturday to beat an in-form team like Fleetwood.
“Had we got the first goal we could have made it a really difficult night for them. Instead of that we have conceded the first goal which gives them something to build on, which is not what we should be doing.”