Alexis Sanchez looked to have handed his side all three points when his free kick was deflected past Ben Forster by James McClean.
But in the 88th minute ex-Arsenal man Keiran Gibbs clipped the ball on to Calum Chambers’ arm and Dean pointed to the spot.
Jay Rodriguez made no mistake from the spot as he struck his penalty straight down the middle.
Wenger fumed on the touchline about the decision and television footage shows Dean and the Arsenal boss in an animated discussion.
And some fans on Twitter believe the referee says “I’m sorry” to the Arsenal boss several times.
An Arsenal fan tweeted: “I’m not a great lip reader but this looks like Mike Dean saying sorry to Arsene Wenger numerous times 60 seconds after WBA scored their pen. Shocking really!”
One supporter said: “Waiting for someone to comment on Mike Dean CLEARLY mouthing “I’m sorry”, to #Wenger.”
Another frustrated fan wrote: This cap it all…Mike Dean telling Arsene Wenger I am sorry several times after he gave the penalty.”
But other observers were quick to suggest Dean was telling Wenger “I’m talking’.
One wrote: “Mike Dean is horrible – repeating ‘put the ball down’ to Phillips earlier, then repeating ‘I’m talking’ to Wenger then. Over officious.”
Another said: “Mike Dean didn’t say “I’m sorry” to Wenger, said “I’m talking” multiple times.”
In his post-match interview, Wenger made no reference to an apology from Dean but made his frustration clear about the standard of refereeing in the Premier League.
Wenger said: “I think many years ago Mike Dean and myself fought hard for referees to become professional and they do a good job but don’t work enough.
“But we have a very difficult schedule and I believe we fought hard to win the game but didn’t because of a bad decision.
“He (Dean) didn’t see it. There was a player in front of him.
“That’s why I questioned his decision, he didn’t see it.”
