Thanks for your responses. So, according to soap, a phase-detect is only done once, right? So if there's an error nothing can stop it from happening. That's annoying.
That's the beauty of it. It's FAST.
Errors /should/ be very uncommon. In the old days you'd get your system recalibrated if need be, now you can dial in a correction factor. That's cool x10 in my book.
But can't AF-C mess up as well?
It can - and it should, as it is focusing the same way, it just focus multiple times per unit of time. (Don't know the rate).
It /should/ keep splitting the error and get closer, but w/o a malfunctioning lens I can't prove this, and I haven't read any direct commentary on this situation from a trusted source.
This is with AF-S on by the way, not AF-C, which is constantly updating focus readings.
Yea - absolutely. I assumed that was implicit, but you're right - I should have been explicit.