It seems fishing lures in general are hard to patent. As a result, some lure makers copyright the name instead of patenting the design. The hassle of pursuing patent rights is well known.

In regards to the question of "Whose pattern", the following shows that even fathers and sons cannot agree.

Most know about the McNally Magnum, Tom McNally's creation. A while ago I came across the McNally Snake, a fly that Bob McNally claims to have inverted. In Bob's words, it is the same as the Magnum except that the wing hackles are tied curving inward rather than flaring outward Magnum style. That created a warm "father and son" image in my mind for a while. But, shortly after hearing about the Snake, I came across one of Tom's statements about the Magnum which says that the saddle hackles of the wings can be tied "curving inward or outward." Was he in effect saying, I invented the Snake, not Bob?

Tom has gone to a place above those concerns; and Bob is not pressing to call it Bob McNally's Snake. So the advice to let it go, frequently given here, seems to be right on