Sterry was punished for bringing down Aaron Collins deep into stoppage time and was shown a straight red card by referee Carl Brook.
And Pools were doubly punished as Antony Evans found the back of the net in spectacular style from the resulting freekick to condemn Lee’s side to defeat at the Memorial Stadium.
Sterry will now serve a suspension for the second time this season having been dismissed for an off the ball incident in the defeat to Forest Green Rovers at the Suit Direct Stadium back in November.
“It’s difficult. Obviously you’re frustrated with the way the game had gone so you’re trying to get back into it,” Lee told The Mail.
“I don’t know if he hesitated or the lad just got across him. I don’t know if Timi has managed to cover round or not so I'll have to have a look at it.
“Sometimes just that slight hesitation can cost you.”
Sterry’s sending off was one of two decisions Lee was keen to look back on after the decision to deny midfielder Gavan Holohan a penalty.
The Irishman went down following a coming together with Rovers defender Cian Harries in the first half but the referee remained unmoved despite the Pools protests.
“I haven't seen it back but Gav Holohan has chested the ball and he’s had his legs taken from under him.
“Anywhere else on the pitch, like I said to the referee, and it’s a foul. So I don’t understand why it wouldn't be in the box.”