I Didn't Need to Lance It

What the heck it going on here? As if that last bulge wasn't bad enough, this one looks like I somehow managed to get a golf ball lodged in my rear tire. I've ridden a lot of different tires over the years, including others in the Maxxis line (this one is a High Roller II) and never had this happen even once, let along twice. Funny thing is, it wasn't there when I started out, but developed while I was riding - hmmm? A couple miles, or so, after stopping to take some photographic evidence, there was a "pfffffft" sound, not a "pop," not a "bang," not a "boom," nor any other similar explosive-type sound, just "pffffft." Stopping to have a look, I spun the wheel round, and... nothing. It was gone. I could see where the bulge had been, the skin of the tire was kind of crepey-looking, and there was some wet grit where some sealant had come out and mixed with the dirt, but the tire didn't go flat and so I rode on.

Since I have never had it happen before, I am guessing this one tire is defective in some way, but I don't know, Anyone else have it happen to you?