Without a doubt using the same passwords for multiple websites is a recipe for disaster but this possibility is probably not directly related to the OP. Also, I have read several account-recovery threads where hacks (or alleged hacks) have taken place but none claimed their Bitcointalk account was hacked just after they joined another forum whether they were using the same/different password.
A full detailed explanation of how any hack took place will help guide other members to take valuable precautions.
Since you’ve already recovered your account, I don’t know if you’ve already mentioned in this thread the possible reason why you got hacked. What do you think is the reason you got hacked? Did you teleport to Altcointalk using the same login credentials? Be extra careful now because it’s possible that not just your Bitcointalk account was compromised. It might also be time to update your passwords for your other accounts like email or social media.