10-15 minutes of cooling off is not doing what you or he thinks it is.
If it were venting for an hour, I could see that logic but what you've typed makes no sense. To me anyway...
I cook my briskets to 160°-165° degrees, then pull of the smoker to wrap. It then gets smoked until probe tender, vented for a few minutes, wrapped back up and put into the warmer. There is not enough time for bacteria to form. I'm fairly certain most on here do the same and have done for a long time with great success and no one getting sick.
I would normally agree that a brisket with an internal temp of 200ish could be safely vented for a few minutes. But it got me thinking and I did some reading about safe temps and bacteria growth. I would have thought that meat being that hot on the inside, vented for a few minutes, then wrapped tight again, would reheat the surface to above 160 or above, killing any bacteria that may have begun to grow. I did not realize that the bacteria could quickly produce toxins that are not destroyed by heat.
I still think there is little chance of this happening and we have all done and gotten away with way worse situations. Hell, they say that all beef should be cooked to at least 145 degrees internal. There went the medium rare steaks that a lot of us love. By the time you let that 145 ribeye rest a little, over-run has it above 150 degrees. Shoe leather!
I saw a video of one of the most popular brisket joints in Texas, smoking a brisket to 170ish, wrapping it, and taking it up to 190. then holding it (still wrapped) in a 160-degree oven, warmer, smoker, or whatever, for as much as 24 hours. I would like to try this. I'm sure the bark won't be quite as nice, but if it is good enough for them, I'll give it a try too. The good thing is, that there seems to be little chance of bacteria getting to it because the venting step is eliminated.
I guess you can never be too careful but then you can also overdo it and kill the Q. I have known a lot of people, (myself included several times) who have gotten sick after eating at restaurants. But I don't ever remember anyone getting sick after eating homemade Q. That leads me to believe that most of us are much more careful than we think. Now watch, I just jinxed myself. We will probably be hurling like crazy soon, lol.