It absolutely depends on the combination of things he's going to do with the camera.
I'd also base the decision on camera + first three lenses. Even if he just went with a kit lens in the beginning, it's worthwhile costing up the next few choices... what portrait? what fast street prime? what wide angle zoom? There are some great new systems out there but they fall down because they lack lens coverage in one of these categories - or you find that lenses are too expensive.
Personally I'm growing tired of Canon. I don't think they're innovating that much at the moment, I think they're just trying to hang on to the remains of the DSLR market. They have some excellent lenses - but their lens costs are starting to get out of control. This is why your friend needs to look at the costs of second, third, fourth lens - because the camera body / kit lens is usually a loss leader to get you into the system.
For DSLRs, I'd probably go Nikon if I were buying now. Nicer and more cost effective flash system, better and more cost effective prime lenses. Sensible prices for pro zooms.
I think the Sony DSLR system is on borrowed time. I'd expect Sony to put more time into mirrorless in the future - I really wouldn't buy into their DSLRs now.
Personally I think mirrorless is the future and I'd go for one of them. Myself, I've bought a Sony a7r and I'm moving off Canon.
The Sony mirrorless cameras are great, the lenses less good. Sony is beating Canon when it comes to full-sensor video, and cameras like the a7r are up with Nikon's D810 for sharpness. The Sony full frame mirrorless lineup has two great prime lenses - for now you need to look elsewhere if you need more flexibility.
If I were your friend I would also seriously look at the Fuji mirrorless range. They're not full frame - but Fuji have such a great range of fast lenses you can pretty much get all the depth of field control and sharpness you need on the smaller sensor. The camera bodies are great too.