Maybe I'm misguided, but my memory of the Podcast is that monsters don't have any sort of formulae, but rather a set of charts by role and level that give you a range of what is acceptable.
So for a pit fiend, you would go to the Elite table, find the "Soldier" column (which means you're emphasizing defense over damage output) and slide down to level 26, and find that it says you should have HP in the range of 320 to 350, AC in the range of 40-45, and so on. (These are made up numbers, of course.)
You then decide that this guy is supposed to be really scary, so you give him top-end HP and near-maximum AC, etc etc.
There's no math behind picking a 44 instead of a 42 or whatever, other than just what feels right and falls in the proper range of values.