Ive used NAP Spitfires and they are awsome, i also used a rage 2 blade on a doe this year and got a passthrough and she fell at 40 yards. I think im going to stick with the spitfires in the future, we will see.

As for your situation, i would think that you still have a dead coyote out there somewhere, as long as you git a vital organ. A well placed arrow will kill an animal even with a field tip on it.