Tipping a porto-john accidentally on purpose

El Paso was a strange place to grow up.  Amongst the numerous peculiarities about the city, one is that housing is relatively cheap.  While there are apartments, there also always seemed to be housing developments on the edge of town, expanding the city's footprint and providing a wealth of low cost houses to purchase or rent.

When I was in high school, several new neighborhoods were being built just a few minutes drive from my school.  At night, when there was nothing for teenagers to do, we'd often drive around these neighborhoods and sometimes explore the new houses.

One night, while cruising around one of these construction sites, we came upon the portable bathroom that served the workers by day.  After a moment of joking and egging-on by my friends, I decided to tip over the porto-john.

Let me add some clarifying detail before continuing.  First, while this new neighborhood was adjacent to a populated one, it was quite a long walk from anything of interest.  That is to say, there were no stores or restaurants nearby.  Second, this was late at night, at least midnight.  Third, there weren't any other cars in the new neighborhood.  I call these things out to note that we had no reason to think anyone else was out on the construction site.

I did a little jog toward the toilet and threw my shoulder into it.   It tipped a few degrees but then settled again upright.  I had expected it to be bottom heavy based on all the liquid in the basin, but it still felt like there was much more weight inside than there should have been.

I stepped back, built up a little more steam, and put all my weight toward tipping over the outhouse.  It hit the ground on it's side with a satisfying thud and splash sound.  Then, from inside the toilet we hear,

"Ugh."

A pause.  We all look at each other like 'Did you just hear that?'.  Then, from inside the toilet again:

"What the hell?"

Another pause, then we all bolted.  We jumped into my friend's car and sped out of the neighborhood.  I watched the porto-john as long as I could, and never saw the person emerge from within.

I felt terrible for having subjected a fellow human to that situation.  Afterward, there were all kinds of questions about what the hell he was doing out there.  

Given that there was no sound the first time I rocked the bathroom, I have to assume the person inside was asleep or passed out.  But why choose to sleep there rather than inside one of the new, unfinished houses?

Was this one of the workers who had nowhere else to go or a vagrant who stopped in for a piss and then passed out?

We'll never know, but it fascinates me to this day.