Thanks Pedota , very interesting post .
Prof Ladkin is a very controversial figure, but worth listening to. He is loved by Airbus, and now certainly by Eurocontrol.
I remember his work on the early A320 logic faults. Very impressive.
For the RVSM in Europe the Eurocontrol study indeed meets the Target Level of Safety . But is is based on total compliance with ACAS RAs ( i.e deviations of a few hundred feet max ) reality is indeed different and pilots reactions to RA are sometimes interesting to watch.
The point is that too little real data exists on the relations ACAS-RVSM to make a generality.
At the moment both Jo Sultana, the Eurocontrol RVSM Project Manager and Prof Ladkin are right. The RVSM TLS is indeed mathematically met , but is one RVSM induced collision per 150 years a realistic figure in real life ?