Bear in mind as an arriving international passengers he will have to go through immigration, collect his bag, go through customs, go landside, do bag drop in enough time before the flight (45 mins?), get through security which rarely seems quick at T8 and get to the gate which may well be in the satellite building being a good 5-10 minute walk.

Frankly if I were your friend I would book a later flight to LAS. If I was carry on only and as I have GE I might go for it myself, but certainly not with a checked bag.

MCT for this type of connection is 75 minutes btw just for information.