The only justification she has against him is if she is a staff in the hotel,even though many guys know hotel receptionists, porters and waitresses do runs too with customers provided you would give them money for it.
You all aren't asking the right question,this story isn't complete. Who is she to him,what is she doing there,was it inside the room or outside,is she a worker in the hotel,is she a HK girl or OS.what time did it happen etc let's keep emotions aside. A hotel room isn't a church.