3. It is a little late to do that thing.
4. It is a little too late to do that thing.
So Linkway, when we say "a little late" for any situation, there is a chance to redeem that situation partially or there is a hope of it, but when we say "a little too late", then there is absolutely no chance of redeeming the situation and there is nothing that can happen if we carry out our act. Am I right in interpreting it this way?It's a little late to apologise, but better late than never. Tom will probably forgive you.
It's a little too late to apologise - the damage is already done, and you've been dismissed for being rude to the boss's spouse.