Dirty Fighting doesn't specify "at your location" so ... you can trigger Doppelgänger to evade an enemy from an other location and then trigger Dirty Fighting to fight it, right ? Even if this enemy is Aloof.

On the opposite, Lucius Galloway gets the clue at his location.

I think a more standard use is to put it in a deck that gets clues thanks to the presence of an enemy (Fake Credentials, Followed, ...) : you lay Doppelgänger on high-shroud locations and when an enemy enters one of them, you teleport there to try to get the clues. And you can eventually combine it with Obscure: teleport to the location, engage, evade, and then get your clues.

Edit: As indicated below, you can't fight from an other location with Dirty Fighting if you don't have an effect that allows you to fight from an other location.