It sounds so easy when you say, and then he just packs it out.

Even boning out an elk you have a minimum of 3 HEAVY packs to carry out, more like 4 loads. If you are by yourself it takes half a day to cape and bone out an elk and when you are done you will be very tired, especially if it is laying on a slope, they are very tough to turn over by yourself.
Then the packing out starts.

If you are packing it out by yourself you are in for a couple days of serious pain.
If you didn' t take the time to work out and get in SERIOUSLY good condition you may not physically be able to do it, unless you get really lucky and are close to a road or are hunting in relatively flat country.
If there are 3 or 4 buddies with you then each of you can carry one pack out and then it is not bad.

Boning out an elk is just what it sounds like. You cut all the meat off and put it in your bags of choice then throw it on the back pack. If you leave the leg bones in it helps if you are going to hang your meat and age it, but adds significant weight.
You can get by without gutting the animal if you know where to make the cuts to get the tenderloins out.