That "offside" was last called in 2003 or something.
If we literally read the rules, this might be offside, but refs never call it. It's like pushing and holding jerseys during corner kicks. Happens all the time and by the rules those could be penalties, but they are never called (Lichtsteiner against Celtic comes to mind, or, in relation to Bayern's "offside", Bonucci's winner against Roma last year).