From the perspective of an audiophile, your friend was certainly given misinformation. However, it doesn't necessarily mean that the salesman wasn't giving the best advice based on his experience as a salesman. It all depends on what your friend is looking for in an audio system. I would anticipate that the majority of customers are looking for features and are not discerning enough to appreciate the difference in sound quality between a good integrated and a receiver.
It's been more than a decade, but when I purchased my Focal 836v speakers I quickly discovered that my Onkyo receiver wasn't up to the challenge. I ended up purchasing an Integra 50.1 receiver and actually still use it in my home theater setup. It's really not a bad place to start. The Denon AVR-X3700 is 4 ohm stable, has plenty of power, and has preouts so your friend has options and will likely keep this unit for a long time even if he gets itchy to move up.
As audiophiles we have to be careful to give advice that is in alignment with what are friends are wanting. It's easy to get carried away and recommend things that we appreciate but are way beyond what they really want or need. I'm not saying that you did this, it's just something that we all have to be aware of.
The real test will be to see if your friend is happy with his gear or wishes that he's gotten something different/better. I'd suspect that he will be very happy and even though he may not have gotten the best deal, he may be happy for a long time to come.