These were internal trial transcripts. To believe that these records were forged is like believing that the records of common criminal trials today are forged. Moreover, these transcripts only constituted part of the evidence examined by the scholars.
Additionally, why do you trust documented false accounts? It looks to me that you're fitting the evidence to your preconceived ideas, rather than pursuing the truth.
As pseudo-justin posted above:
Furthermore, the BBC production does an excellent job of explaining how the myth of the Spanish Inquisition arose in the first place. Anti-Spanish Protestants, mostly Lutherans, were master propagandists, printed and distributed copies of fabricated first-person accounts of Spanish Inquisition trials, and thus effectively whipped up sentiment against the Spanish crown. These propaganda pieces were the primary evidence that historians later used in constucting their accounts of the Inquisition (and most of those historians were Protestant).This is documented.
It's no good trying to explain the concept of "primary-sources" to the self-proclaimed amatuer historians since, people were stupid and didn't write anything down back then. They also didn't bathe, they believed the world was flat, and thought women had no souls.