i've been stung by wasps a few times. they have a tendency to sting repeatedly and do it quickly.
I might have to agree with the yellow Jacket. The one on the leg, (the one I could see easily) looked like a whole line of very quick shallow injections, perhaps three quarters of an inch long. Then a deep hard injections. Then a couple more spots that were hit somewhere between the intensities of the others. After it finally stop hurting none of them are more than red and a small bump.
I had knocked down a couple of small nest. Found and killed one of the occupants but couldn't fine the other. Perhaps that one went up the leg and got me. I didn't rip off the clothes to look for it. Figured I killed it cause it stopped stinging me. Then later I peeled off the bee suit to cool down a bit but didn't think to look for dead critters. So it probably feel out unnoticed.
I use to tape the leg openings shut around my boots but got away from that habit. Just never know whats gonna crawl up there and bite you on the ____.