Partly true, Mad_Jock, I also have heard of that case. However you could also ask for the average hours the students are passing with.
There are schools with high pass rates on normal hours. The only one I can mention without advertising is the one I went to, SFT. They have now gone bust, but although it was not always the case (hence my comment on changing over time) when I first went there as a student, they were getting over 70% first-time pass rates - yet I had no pressure to fly extra hours (in fact I had to pick up an extra couple of hours after my test before I could have my licence issued). There are still schools that do!
Asdvocatus also has a fine point.