I obviously wasn't there, but I'll play devil's advocate. Sometimes kids do something that is mortifying and you just try to get it over with. I prefer to think that the child unexpectedly pulled down his pants and started peeing (I have three boys and they've all done it at one time or another - and it's been mortifying). It's exceedingly difficult to stop a boy from peeing once he has started, and perhaps the looks on the parents' faces were more from their being mortified about people's seeing what was happening rather than their giving people dirty looks for interrupting their planned bathroom break and location.
I agree that it's possible. Especially the misinterpreted look part. When DH sees a woman nursing her child, he tries to give a kind, supportive look. I've seen that look, and it comes across as creepy. I tell him to just NOT look b/c that's better than the look he gives, LOL.
I have a nephew that when he was like 3 or so and had learned that secret he would go outside and pee off the deck into the back yard, I think, just because he could. The go camping and stuff a lot so he just did it. Well, they did finally get him to understand there are places (like camping) that it was ok to go find a bush and go if he needed, but if he was visiting places that wasnt the right thing to do.
Reason #1 I have never let DS pee in any bushes, even though we were camping quite a bit for awhile. We camp in state parks, there are bathrooms, we use those bathrooms even though I hate them. No bushes!
Unless the kid had developmental problems, 4 or 5 is old enough to know to wait until you get to a restroom. Yeesh.. I'm sorry, it's just gross to me.
You'd think, but there CAN be a perfect storm of events and forgetfulness... DS was out of diapers by 2.5 (he would have preferred it to happen at 2, but I was nervous), but last summer when he was a new 5, he had to "go" during a mom/son trip to DLR. But we were right about to get on a ride, he said he could hold it, we went on the ride and forgot about his need. One thing led to another, and an HOUR later he finally realized that he very very very very much HAD TO go, and there was no waiting. Poor munchkin, he was so embarrassed. As soon as I realized the situation (we were looking at pins in the shop after Buzz) I picked him up and put him on my hip, because I wasn't going to embarrass a 5 year old with wet pants, and sometimes the pressure of my hip can help him stop. But he couldn't stop, and I carried him on my hip, to reduce his embarrassment, from Tomorrowland all the way to our Paradise Pier Hotel room (long way). Changed our clothes, went and had dinner, all was well.
So you can have the expectation that a kid is old enough...but if there's enough "fun" going on, things can get forgotten.
Do I think those things happened in this case? Naw. Do I hope it? Oh yes.