Mummy Mandarin: A Question

Since all I can say in Mandarin is 'hello,' 'thank you,' and 'shut up' (courtesy of Taiwanese dog owners at 2AM when Fido wouldn't 'mo lun cho')*, I have a Mandarin question for those of who you speak it.

I have noticed in the last few period films (Warlords, Three Kingdoms, Red Cliff, etc.)  that actors who can speak Mandarin are nevertheless dubbed by others. The explanation has often been that the Mandarin dialect used in the film is 'historically correct,' i.e. significantly different from current Mandarin, so they have to get people who can speak it to record the dialogue.

Well, I don't think that's the case in The Mummy. It seems like it's (as Dave Chappelle would say) regular-@ss Mandarin.

Is it?

I'm certainly not shocked that Hollywood would gloss over linguistic accuracy; I just want to see if my ear actually discerned something.

My nose sure did.

* I know it's Cantonese. It was a joke that has obviously miscarried.