He may want to consider the fact he is probably less dependant on the drug. When you run out two weeks early you're obviously only taking it for two weeks before you're ill again, meaning compared to scaling back from one month (continual dosing) he is going to have milder withdrawals. Each month that he does this it will get easier and easier, and with the somewhat mild dependancy that he had the difference in what he felt may have been a lot compared to the month before.
In the past I've had this happen when I ran out early. Each month got easier, then one month I noticed a bigger difference compared to ones before since my body was starting to adjust to this pattern (to a point where I didn't even vomit), so I kinda put the facts together and realized what was happening, and it makes sense if you think about it. At first you don't notice a huge difference because it's only happened a couple of times, so the body isn't used to it so homeostasis doesn't really begin to shift. The more often this happens means the body is going to start adjusting quicker as it assumes it will be the new normal until it reaches the point where the body reaches a balance and you won't feel a whole lot better, but you have reached the new equilibrium. But, that transition takes time, so it makes sense that he may not notice much at first (the last few months). I bet any money if he started stretching it out over the month his dependancy would grow since his body isn't used to taking any breaks. Right now he's in the transition stage and getting closer to what a two week dependancy feels like compared to a multi-month run (which is a big difference).
Let us know how it goes Froglegs, though I think you'll be in the clear, other than the pain that you're dealing with, which I don't know how you can deal with. I don't know how you can deal without your pain meds, but best of luck to you.
A trick I used when I couldn't stop using extra meds due to increasing pain (and a doctor who wouldn't flex my script to fit my tolerance) was to give my script to someone I trust, like a family member and get them to set out your doses for you and a little extra if you need it. I know you don't wanna hear it, but maybe if you can go without your meds pain-wise, then maybe stay off of them for a while and get someone to hold them so you won't have to go through the cycle.
Anyway, best of luck man. Take care.