Is Scientology a religion or a cult?
You can watch John Sweeney's Panorama film "Scientology and Me" here. Sweeney is the first to acknowledge that his remarkable outburst in this documentary -- notwithstanding the pressure he was facing in that moment -- is completely unprofessional and unacceptable.
I've some sympathy for him, given the frankly weird behaviour of some of those following him around. The bizarre series of events culminating in this emotional collision began when Sweeney questioned whether Scientology is a "cult" rather than a "religion".
In forming your view on that question, you may wish to view this: World in Action's 1967 documentary about the founder of Scientology, L. Ron Hubbard.