Ha, here is the big fight between the muzzled OK seismologists, and the usgus! This earthquake is right on the nose at 4.0. If the okies believe this, then a lot of wells have to be closed, especially those huge dewatering wells. Of course they'll call it an M3.9.
But this is in the zone of mixed thrust and shear. The shape of the felt area suggests an oblique thrust, but with a very high intensity in the potential hammer zone. I doubt that the usgus will discount this, but who knows?
If the earthquakes are rising again, then we'll soon get something that is so over m4 that there is no dispute. :)
Update: Yeah, OGS M3.9!
Update2: Deep breath, I'm getting nasty again. Good thing nobody is reading this.