Using the example for "he" it can either be: He overdid it He has overdone it (which can be abbreviated to "he's overdone it") "He overdid it" refers more to a past action - "he has overdone it" would make the action (whatever he has overdone) seem more current, if the "overdoing" was even happen at this very moment.

In addition to what Chris said, we use "overdone" in cooking a lot-- if something is cooked too much it is "overdone." "I overdid it on the charcoal and now my grilled steak is overdone." (In America, at least, you will often hear people say "I overdid it on the ______," like "I overdid it on the beer last night and I feel terrible." But it's closer to slang than proper English).