It's still better IMO to taper crimp auto pistol cartridges.
I suspect it was discovered in the early days of straightwall auto cartridges that if you made the chamber a tad longer and used a slightly heavier extractor, function problems were noticeably reduced. But there are still some pretty tight chambers occasionally encountered today in modern target pistols and in older milsurps and prewar commercial pistols.
Not all chamber reamers are created equal, and their dimensions change with each sharpening, the chambers they cut slightly smaller. When is an expensive reamer finally too small and needing replacement? This is especially true of older early semi-autos, including those produced during WWII by slave labor. Today we have standard accepted chamber dimensions and acceptable variation. Then, a different tool maker at every factory made his best guess when he ground a new run of reamers. I have actually had to initially TRIM cases for one ancient 9mm and a pair of .32ACP's. Those pistols headspace ON THE RIM. Technically all three have insufficient headspace and with a GO Gage chambered would not go into battery. The 9mm, a Luger, must have been a jam-o-matic with mil ammo, but it functions well now with taper crimped handloads. A roll crimped round went go too far in and the firing pin didn't hit it, there is enough play in the extractor, but that was the clue that helped me to solve the puzzle as it caused me to stop guessing and measure the actual chamber dimensions. It is a rare box of factory ammo that will function properly in it, if at all, glad I don't own it. He has a thousand cases of the correct length that he loads cast bullets in for it and he is happy because he loves to shoot it and nothing sucks more than an expensive antique pistol that won't work. I shudder to think of a soldier carrying it in battle, even a German soldier (probably why it's in such good shape - it had obviously never worked right). The .32's, a Walther and a Browning, had the same issue, but them I cured with a reamer. But if I hadn't had to take the time to figure out the Luger's problem and a way to load for it without taking a chambering reamer to it I'd never have figured them out. These are extremes and I use them only to illustrate the worst case and to remind that whenever you come upon an older gun, you'd better check it over pretty thoroughly. There are reasons for some of our handloading "rules".
It really isn't an issue with most modern pistols how you crimp, as long as you do it correctly, but I still prefer to do my crimping for them in a separate step, which usually means a taper crimp, and I continue to hate roll crimps for anything but revolver rounds. In a modern pistol with a good extractor and plenty of elbow room in the chamber it really shouldn't make a difference if you roll crimp them.....usually. And it does save a step in the production, a real advantage in a progressive with a limited number of die stations. But I run turret, not a progressive, have room on it for all the dies I could ever need, and (NOT to cast aspersions on your friend in any way KD - if it works, don't fix it) I hate roll crimps anyway. I may have mentioned that.
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My point was not that a roll-crimp was better but that the case seldom headspaces on the rim. I agree any auto will probably work better with a taper crimp or "factory crimp" but recognize the case mouth just doesn't often touch in the chamber. What Versifier said about crafting and sharpening chamber reamers is probably the key here. 
