So basically what you said is you suck at managing and in fact have someone else do it for you in the form of HR.
Errr... HR always do the dismissal in large companies. They manage the process (collecting keys, revoking access, escorting from the building) and they make sure it's done within the relevant statutes. It's their job to manage the exit of former employees. In contrast, the boss's job is to manage people who work for him. This one wouldn't, any more.
You make the same threats statements, you just try to sugar coat them.
People who are made to feel stupid when they are wrong will tend to cover up their failures and they won't be happy in the workplace anyway. Managing people is about sugar-coating things sometimes, so grow up.
You just don't have the courage to say what you mean.
The attitude displayed in the grandparent post is a good one, the fact you don't appreciate that, may indicate that you are wrong rather than he. The attitudes expressed here make me not want to ever work for you (do you manage people?) - because you sound like an asshole if you manage with that kind of "courage"...