Probert blew for full-time just as Jonathan de Guzman homed in on goal behind the Gunners' defence, leaving Swansea's visiting fans, the team and manager Monk furious despite a late own goal earning the Welsh side a valuable 2-2 draw.
"I have told the referee I think it's a very poor decision. I don't understand it," the manager told reporters.
"I am not saying we are definitely going to score but he was going to be clean through.
"I have never had something like that in all the games I have played in. Normally they blow the whistle when the ball is in a neutral area."
Swansea are 15th in the 20-team league, five points above the drop zone, and a victory would have moved them two places higher in the standings.
Monk's anger was based on the fact his side equalised right on the 90th minute, and so the referee should have extended the four minutes of added time already calculated.
"They told us it was going to be four minutes at the end of the game. We score in that period so they add an extra minute on, so it's five minutes minimum - and I stress the word minimum," he said.
"Then we are clean through on goal, 99 percent sure a goal-scoring opportunity is going to come, and they blow 30 seconds short."
(Writing by Ossian Shine; Editing by John O'Brien)
