cooking times and temps

Welcome to SMF!  Be sure to stop in over at Roll Call and say "Hi" so folks can give you a proper greeting. 

10 hours for pork ribs, which fall off the bone (trust me, they do), is a bit of an overkill when they can be done in about half that time at 225-250 cooking temp. 

Chances are good they are getting over (or close to) the 140 mark in four hours.  Until meat stalls, it seeks equilibrium with the ambient temperature fairly quickly, that's why folks are always concerned that cold meat temp is rising too quickly.   

Welcome to the forum from Oklahoma. 

If I were new to smoking, I would go to the upper right corner and take a look at the multiple posts of the 2-2-1 method for smoking pork ribs and get a consensus of what you find for a starting point.

While your friend is definitely doing low and slow, to me he is taking it to the extreme, and going to a lot of work doing it.

I think you will find in general, most of the people here smoke at least a 225' minim. 

Smoking by time is virtually a general off the wall guess.  New smokers, like all of us have been, do not understand, every piece of meat is different.  Reading a temperature probe is the law.

We are all practicing, just make sure it will not be so bad you can not eat your mistakes, the dogs might like it, but that is not what we are striving for.

I would suspect after a couple smookes, you might be able to dazzle your friend

Let us know how it is going.