The Inquisition could be turned against Muslims via trumped-up proselytism charges

Evidence

Mudejars were especially worried that the Inquisition would begin to institute proceedings against them. Even though Muslims may have been aware that they were, strictly speaking, outside the jurisdiction of the Inquisition, they knew that charges might easily be trumped up. A Muslim who tried to persuade a fellow Muslim who had become a convert to Christianity to return to his old beliefs might be subject to an Inquisition trial, for example, and it was easy to lay accusations of proselytism. — L. P. Harvey, Muslims in Spain, 1500 to 1614, 438