All that corruption and insubordination exhibited by ONE member of the Order, until Act III which is what I said.
More than one.
Kerras, Alrik, Metten, everyone who was under them that didn't report their abuse to Cullen or Meredith, two of whom I mentioned are running ramapant in Acts 1 and 2, unless Kerras dies by Hawke's hand in Act 1.
Also, why was Emerick, a decent templar who was genuinely trying to do his job and conduct an investigation into practically confirmed blood magic, with the evidence gathered by Hawke, human remains, demons summoned, a man fleeing the scene, not only ignored by his superiors, but he was actually limited in his investigation by them, and received no help from the Guard or the templars and eventually told to stand down, cease and desist, because he convinced some guards to raid the manor of a noble, who turned out to be a blood mage, and had a connection to Quentin as his former apprentice?
And Cullen's own codex says he wasn't promoted on merit, he was promoted to Knight-Captain because his own views on mages (while freshly traumatized from Ferelden) matched Meredith's own.
Add in History of Kirkwall Chapter 4, with the Chantry ordering the templars to interfere with Kirkwall politics because the Viscount was making things hard for Orlais, and it was Elthina who tried and sentenced the Viscount, and you have a long history of corruption within the templars. Not just in abuse of mages, but overall corruption, corrupt in its grabs for power, corrupt in promoting the wrong people for the wrong reasons, corrupt in limiting the real work by templars who are actually trying to do their job, and then, in Act 3, corrupt in seizing power in the city and a refusal to give it up over the course of three years.