Yep, I get this too.
What I noticed is - they didn't want to eat but they didn't want to get bit by the rat either. All the times that my bp did this - he would strike at the rat but not coil. But then, the rat would get comfortable and try to come near the snake again, so he would strike again but not coil... until he finally gets tired of it and strikes and coils, rat is dead, then he leaves it alone. Problem solved.
So, what I've been doing is - if he strikes but doesn't coil, I just get the rat out and wait another week.