Here's what I'd do with ipconfig + ping data, ipconfig shows that it's still normal, default gateway and everything, but can't ping google/the AP, then there is a connection problem between the wifi NIC and the AP, is it channel collision? I don't know, I won't get to that until I get the diagnostic data of the wifi radio connection. Several probes later, I might arrive at your conclusion - but I got there with confidence IMHO, supported with many diagnostic data which then concludes that it's a channel collision. But you're right, you're much more experienced and more knowledgeable than me, I'm bow my head...
zzz2496
I do have my own guesses, but according to my experience, educated guess + some important diagnostic data = 95++% chance of nailing the problem. I personally look for diagnostic data first than guessing first, but that's just me 
That would help a lot...
