Highly carbonated beer...in the carboy?

Quick history, I brewed an extract version of EdWort's Pale ale about a month ago, and my fermentation temperature got out of hand and may have gotten as high as 72. This isn't dangerously high, but it was high enough for the Nottingham to throw off phenols. Beyond that, everything seemed to go perfectly normal and hydrometer sample was still drinkable.

After making a post here to inquire about dry hopping to mask some of the off flavors, I was advised to let it sit in the secondary and/or bottle,which may cause the off flavor to diminish. So it's been sitting in the secondary for about 20 days now at about 68F, and tonight I went down to take a hydrometer reading. My secondary is a 5 gallon glass carboy with an S shaped airlock.

In short, the beer is RIDICULOUSLY carbonated, to the point where as soon as I dipped the thief into the beer, CO2 started bubbling out of solution. There is just a TON of CO2 in this beer. I tasted the sample, and while the phenols were still there, I also had an acidic flavor on my tongue, almost salty. This may or may not be all the CO2. It wasn't offensive, but different. It reminded me a lot of a Farmhouse Ale I recently had at the New Holland Brewery.

Anybody ever have this happen? Fermentation was DEFINITELY complete when I racked to secondary, and I feel like I did a pretty good job of cleaning the carboy before racking. What's going on here? Infection? What's strange is that even with the airlock in place, there was no bubbling action during those 20 days.

Bubbling does not mean fermentation, and non-bubbling does not mean non-fermentation.

I'd say it was still lightly fermenting, just a couple of points worth, and just enough to put CO2 in solution. I would take another reading just to make sure that you are still within a few points of your last reading, then bottle -- if you dare

Every now and then I have a batch that just seems to retain a lot of co2 in solution. I've had hydrometer samples that tasted almost fully carbonated. That's why you'll always hear people saying airlock activity isn't a good indicator of fermentation.

I didn't use the airlock activity as a measure of fermentation. I had a flat reading for three consecutive days (1.014) prior to racking to secondary, and didn't see any signs of (abnormal) carbonation during the siphoning process. I feel as though if I were to rack this to a bottling bucket right now, it would undoubtedly foam over the top VERY quickly.

I'll let it sit for a few more days and attempt to bottle, but this is still a bit puzzling to me.