On page 10 of the topic he states that if your second Simple Action in one Action Phase is spent firing a firearm, and your first Simple Action in the next Action Phase is spent firing a firearm, your recoil doesn't reset until your second Simple Action in the second Action Phase.
I read the whole conversation after it was pointed out. The problem is that, if we are basing the argument on the language which Aaron claims to be doing, then "for an entire action phase" has to modify either "shooting" or "an action."
Aaron argues that "for an entire action phase" modifies shooting. If that's the case then a Simple Action can never cause recoil to accumulate, because - as Aaron tells us- we know the rules of Shadowrun and a Simple Action can never be "shooting for an entire action phase."
There are only two internally consistent readings.
One is that only "shooting for an entire action phase" causes recoil to accumulate.
The other is that only taking non shooting actions for an entire action phase casues cumulative recoil to reset.
Aaron's reading, where taking a single non shooting action resets recoil, is not internally consistent. If that is the correct RAI then the rule will have to be completely rewritten.