One is that the CEO was asking for a bunch of "above-and-beyond" work. The other is that there was an implicit agreement for such work, but Belgian law made it impossible to explicitly contract for. In the former case I have no problem with the employee, in the latter case he sounds like a pain to work with.
And make no mistake, there is an implicit contract at nearly all jobs. Typical clauses might be "CTO filters BS from above so developers can do real work" or "go ahead and take reasonable flex-time in spite of what the official policy is, but be available for crunch time". Even in a flexible place like the US, it's simply logistically impossible to encode everything in a contract. The closest anyone has come to it are union work rules, disaster that they are.
What "find an employee with passion" really means is "find an employee who's attitude fits better with the implicit contract".