I can't really remember how many people I've sent solo personally, all I know is that they all survived the experience and no aircraft were ever broken, but I suppose because I don't feel the need to state the bleedin' obvious, I'm of course an appalling instructor and the reason this industry is in a parlous state...
None of the FI's I've worked with both as a CFI or back when I was an FI(r) have ever killed people by sending them off too early either. Funny that.
I can only think of that one horrible accident in Southend where a student on their first solo died, that really is a nightmare, but it shows how it can happen and that you can never become flippant about this part of the course.
There is more to teaching people to fly than just ticking boxes. If FI's don't use their "gut feeling" and experience to help drive their actions, then they are the most useless FI's ever to have sat in the cockpit of an aircraft.
Process is all very well, but it has to be combined with a bit of nous too.