Spain has not taken very good care of its patrimony, and a lot of records from the fifteenth and sixteenth century are either damaged or lost. That said:

While some more recent studies (cfr W. Monter, Frontiers of Heresy: The Spanish Inquisition from the Basque Lands to Sicily (Cambridge: Cambridge UP, 2003)) have postulated a fairly low death rate, conviction during the Spanish Inquisition was almost certain.

It is quite likely that your friend has conflated the Spanish Inquisition with its much less bloody forebearer, the Papal Inquisition. This latter institution was comparatively mild, except in the south of France during the Albigensian Crusade in the 13th century, and persists today as the Congregation for the Doctrine of the Faith. I've written up some bits on the Papal Inquisition here and here.

According to John F. Chuchiak's The Inquisition in New Spain, the bloody nature of the Inquisition is indeed a myth. While torture was a part of interrogation, it was done under very specific circumstances and was, at least on paper, not intended to inflict permanent injury or death, or even bloodshed (although exceptions certainly occurred). Conviction did not necessarily mean execution - most sentences were to publicly admit to and refute your blasphemy at an auto da fe. You'll note that the Wiki article mentions "burning in effigy" - a person who might have fled an Inquisitor or died before sentence could be carried out could still be symbolically burned. The numbers of those who were "penanced" are also much higher than those who were executed. Penance could range from simply saying you're sorry to being whipped, exiled, sent to a convent/monastery, or a combination of these.