If you have believed corporate brochures, government oversight agency assurances and the media about how animals are only mistreated is very rare occurances, you need to look again.
Actually, you are somewhat right. Government agencies like the U.S. Fish and Wildlife Commission and the CDC treat the HSUS's propaganda as more or less reliable information. The FWC quotes HSUS's sources when filing environmental impact statements. The HSUS is run by Wayne Pacelle, one of PETA's drones.
The HSUS essentially tries to make PETA's radicalism look respectable. They're not very good at that.
Rick Berman's material is as reliable as it can be made by tracing it to primary sources.