I had heard a similiar story from another Fikes researcher that Mallie and another Fikes brother may have had dealings with an outlaw gang in Tennessee then fled to Oklahoma. I too, have found no proof of this so far.
Another researcher has contacted me requesting contact information on Cleve Fikes, if he is still living. If you are of this line please contact me directly to discuss details.
I'm happy to share info from our line if you'd like it.