I don't think that necessarily true when it comes to refereeing decisions. It certainly helps that the top teams attack more so will get more questionable goals/penalties, just as they'll get more goals/penalties overall but referees are human and it makes sense for them to err on the side of a big club. Why risk the wrath of Ferguson/Wenger/Mourinho who might then object to you reffing their big games in future when the alternative is to piss off Eddie Howe/Pulis/Joe Bloggs who no one really listens to.
I'm not blaming refs or the big teams, with the exception of serial cheaters. It's just people protecting their career prospects, as we all do. Just a theory anyway.