Why does the adjective "award-winning" mean "having won an award" as opposed to "winning an award" ?

When we say "fire-spitting dragon", "crime-fighting heroes" or "tough talking manager" we mean that the dragon spits fire, the heroes fight crime and the manager talks tough at present .
Fire-spitting dragons are mythical, crime-fighting heroes are fictional, and some tough-talking managers are dead - so none of them are doing that now. It describes a capability.
But, if an author has the ability to win an award but hasn't won it yet, can we call him an "award-winning author" ?
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No, he'll have to have won one. And the dragon will have to have spat fire, etc.
But, if an actor who had won an award a long time ago retires from his profession. Can we still call him award winning ?

This is clearly in contrast with "This is very slow moving vehicle", because this sentence means that "the vehicle" moves slowly.

Whereas "the award-winning actor" in the first sentence doesn't mean that "the actor" wins awards. It just means that he had won an award once.
Yes, as long as the actor/actress have "proven" they have the capability of winning an award (to prove it, they must win it first).

So as long as they have won one, no matter how long ago, it means they are capable of winning one and you can call them "Award-winning actor/actress".
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Just as with the retired actor who is 'award-winning', the car could be retired and still 'slow-moving'...if it is ever started up again.