An untold story of Peruvian plumbing

It occurs to me that in my recent post on toilets around the world I omitted a story of Peru. This isn't a story of an oddly located toilet. Nor is it a story of a particularly unusual or disgusting toilet. It's just something that happened in Cuzco.
We had been to Puno and travelled back from there by train to Cuzco, a journey that even on schedule takes eleven hours. We stopped in Juliaca and again at Chuquibambilla and at each we were delayed in starting out again. The result was that, after a fourteen hour journey, we reached Cuzco at around eight thirty and then piled into a minibus to drive into the city. Twenty minutes later we had unloaded our gear into rooms at the Hotel Carlos V. Twenty minutes after that I was eating pizza in a tiny local restaurant and twenty minutes after that I was upstairs in the Cross Keys pub drinking a bottle of beer and listening to a splendid mix of Lou Reed, Bon Jovi and AC/DC.
I stayed there drinking and playing pool until about one in the morning when I decided that I was drunk enough and should head back to my bed. My temporary room mate, a Danish teacher, was, while not exactly a teetotaller, a rather more modest drinker than most of us and had left straight after the pizza, so I tiptoed in as softly as only a very drunken man who has been awake for about eighteen hours can. Somehow I managed to avoid waking him.

I know what you are thinking. What has this to do with toilets. Patience, I'm getting there.
Before I climbed into my bed, I decided that it would be wise to go to the toilet and relieve the pressure from all of that beer. It was, after all the first time I'd had any en suite facilities for almost two weeks. So I tiptoed into the bathroom, did what I had to do and flushed the toilet. I turned to leave but I was vaguely aware that something was wrong. The toilet was still flushing. And still flushing. And still flushing.
And it was loud. The kind of flushing that rattles all the pipes in the whole building. The kind of flushing that shakes the cistern. Certainly the kind of flushing that wakes up your Danish room mate.

It was clear that until the flushing stopped neither of us would get any more sleep. We tried, sober man and drunk man working in imperfect harmony, to fix it, but half an hour and a whole roll of insulation tape later it was still flushing and my room mate was extremely annoyed. He went off to seek an alternate room and fifteen minutes later the staff had found one for us. We moved in and he climbed grumpily into his bed.
By now my bladder was bursting again so I went into the toilet. It was about three O'clock. I did my business and turned to leave. As I did so I flushed the toilet.

I'm sure that you can guess what happened next.