You have been watching too many Dan Brown movies. The very fact that Luther died as a result of his own excesses is proof that there was no "hit" out on him.
Your biases are tainting your interpretation of historical facts. Set your religious prejudices aside and simply look at the facts without an elaborate manipulation of them. History really isn't that complicated.
To preserve his life Luther hid out at the Wartburg Castle in Eisenach using the name of Knight George. While there he worked at translating the New Testament into German.
Just keep looking to the inquisition to see what he had every reason to fear from the power hungry Roman church