United's keeper came haring out of his box to meet a Simon Mignolet goalkick but misjudged the situation, allowing Emmanuel Dennis to lob into an empty net.
Clement rapped: “It's a clear penalty. If you go with two feet forward against the leg of somebody it's a red card."
Solskjaer did not directly blame Romero for the goal but said his team switched off.
The Red Devils boss said: “They were strange goals for both teams.
“Their throw-in led to ours and a long kick straight through the middle for theirs. It was a lack of concentration from both teams."
He also blamed UEFA's ball.
Solskjaer added: “It's just different and difficult to play with. You can get one and try! It's light.
“But it's the same for the two teams, of course. But the conditions weren't nice, the wind and the rain.
“But anyway, strange goals for both teams. Their throw-in we scored from and a long kick straight through the middle, so lack of concentration probably from both teams there.
“We needed to make everyone part of the squad (so I made changes), gave them games.
“We've got so many games now, so we got an away goal, we got a draw. We go home next week so hopefully we can finish the job."