2. As long as you're employed, you either speak the company line, or carefully avoid commenting, in order to avoid breaking rule 1. If you can't neither avoid commenting or lying, you should quit.
3. Once you're no longer employed, you should avoid spilling company secrets, disclosing confidential information, etc. Beyond that, see rule 1.
I'd be concerned if he:
1. Went to conferences and recommended MySQL, despite thinking it was a bad product
2. Went to conferences and trashed MySQL, despite being employed in part to promote MySQL
Both of those would be, in different way, unprofessional. But what he did? Seems fine to me. I certainly don't think he was obligated to share his unvarnished thoughts about MySQL, but I don't think he was obligated not to either.
1. At all times, you should tell the truth.
2. As long as you're employed, you either speak the company line, or carefully avoid commenting, in order to avoid breaking rule 1. If you can't neither avoid commenting or lying, you should quit.
3. Once you're no longer employed, you should avoid spilling company secrets, disclosing confidential information, etc. Beyond that, see rule 1.
I'd be concerned if he:
1. Went to conferences and recommended MySQL, despite thinking it was a bad product
2. Went to conferences and trashed MySQL, despite being employed in part to promote MySQL
Both of those would be, in different way, unprofessional. But what he did? Seems fine to me. I certainly don't think he was obligated to share his unvarnished thoughts about MySQL, but I don't think he was obligated not to either.