Hmm. I don't see anything about such an incident in the press. Nor has SAF panned anything but the lack of extra time.
manutd.com complained about Owen going down (here I'm sure they're wrong) and about Welbeck going down in a challenge with Howson. (manutd.com, "Howson bodychecked him in the area", uk.eurosport.yahoo.com, "He went down very easily" - pick your poison).
Oddly, eurosport (and not manutd.com) reckons there was a chance at the 40th minute, with Becchio perhaps fouling Berbatov during a corner - "it might have been a penalty had referee Foy seen it."