Having read ettore's post one thing here springs to mind.
Note, if the Saab pilot only had the runway in sight at 1.3 NM and was still at the required safe altitude above the ground of 974 feet, it would have required a rate of descent to land the aircraft of some 1,700 feet per minute to make a 50 ft. threshold crossing height. That's a real plummet.
The question is
did the pilot of the Saab descend at such a rapid rate?
Of course, we will never know but my point is how often are the written procedures deviated from based on "local knowledge", perceived passenger comfort or "It'll be alright - it has always worked before"?
It has been mentioned previously that descending below the minimum altitude is illegal - but surely, as long as nothing goes wrong it is very difficult to prove. Is it more common than we think and even endemic in some places/ on some approaches?