After taking the lead through Antoni Sarcevic in the tenth minute and regaining it, following Gavin Massey’s late first-half equaliser, nine minutes after half-time through Matty Kennedy, Argyle suffered Valentine’s Day heartbreak when Massey and Sandro Semedo scored late on.
As well as failing to take advantage of leaders Doncaster Rovers’ latest slip-up at Carlisle United, Argyle saw Antoni limp out of action after having his Achilles tendon raked by Leyton skipper Liam Kelly.
The foul was one of several that Argyle manager Derek Adams felt referee Chris Sarginson failed to deal with properly.
“The referee didn’t have a good night,” said Derek. “I’m really unsure how Leyton Orient had 11 players on the park: Kelly should have been sent off for his tackle on Sarcevic; [Nicky] Hunt should have been sent off as well – how he stayed on the park, I’ll never know.
“His first tackle in the middle of the pitch, he should have been booked for; he’s then had numerous challenges after that; he’s kicked the ball away quite deliberately, as well...if that’s not enough...the referee has got to have seen that. Throughout the night, big decisions, he got wrong.
“Over the night, the referee didn’t have his best night. The referee didn’t control the game in the right manner.”
With Nauris Bulvitis taking over from the injured Sonny Bradley in the middle of the back four early in the game, Argyle’s defence failed to get to grips with Leyton’s pacy forward line, led by the impressive Massey.
Derek said: “We had to change our team about – that’s just natural – but we weren’t hard enough, defensively; we allowed them to get in and cause us trouble.
“We were the better side in the first half; in the second half, I thought Leyton Orient were the better side.
“We didn’t defend well in the second half. To be in a position when we were 2-1 up and under no real threat and then, all of sudden we lose 3-2, we didn’t defend well enough. In the end, [Leyton] have won the game when we could have been 3-1 or 4-1 up.
“We had chances in the game. I thought we played really well in the first half and should have been out of sight. But we weren’t and Massey caused us problems.
“He was the best player on the park by a mile. He ran at us and did really well.”
Perhaps the brightest spot on a disappointing evening was the form of Matty Kennedy, who scored a fine goal and looked bright all night.
Derek said: “He was lively, and Sarcevic scored was well. We were looking like a really confident side but things went against us that we didn’t deal well with.”