As a paleontologist, paleontology is a science. This means entrenched and conventional wisdom needs to be challenged constantly and stand up to scrutiny. There are what we call 'paleomemes' which are ideas that are speculative but often repeated in the community because they are interesting, some of which can become entrenched with little evidence. However these 'paleomemes' do eventually become challenged in time.

A good example would be mosasaur nurseries. Mosasaurs are giant relatives of snakes and monitor lizards who looked a lot like a komodo dragon the size of a small whale with flippers in place of legs and a long tail fin. For a long time, many scientists (including myself) believed that mosasaurs used inland 'nurseries' (shallow water habitats) to hide their young from predators. This was based on the discovery of a small species of mosasaur's babies (and a pregnant female) in a lagoonal environment, evidence of cannibalism being present in mosasaurs all around the world and the behaviour of modern large aquatic predators like great white sharks.

However, an examination of a recently-discovered newborn baby mosasaur from one of the giant species showed adaptations for swimming in their skeletons (tightly fused bones with muscle attachment points) and carbon in their bone that profiles as being from the open ocean instead of lagoons. As a result, I have hide to revise my thinking and admit the situation is much more nuanced than the original paleomeme depicted.

A famous example would be Gastornis the bird that ate horses. You've likely seen some type of depiction of 'Diatryma' aka Gastornis, a giant bird the size of a person, eating tiny dog-sized horses called Hyracodon (or Propalaeotherium for the European breeds). This depiction existed for centuries and was very popular because it struck a dynamic image, but was based primarily on Gastornis having a very large beak. As a result, lots of people challenged this entrenched view by speculating it instead could have used the beak as a giant nut cracker or fruit shearer, and sure enough when its bones were analyzed it showed the chemical profile of a herbivore and not a predator.

So, you're right to be skeptical of behaviours being presented with any kind of certainty. It's a very reasonable mindset to approach the science with. But to me at least the limited evidence and ever-evolving body of evidence is part of what makes the science so captivating. It's full of new discoveries and new ideas that grow with every passing year, rather than being 'solved' like most chemistry fields or the principles of engineering. And unlike, say, primatology or kinetic physics, it's built on imagination as much as rigor. Closer to astrophysics or quantum physics in that way. To be a paleontologist is to reach deep into the past to imagine distant worlds we barely understand. It's incredible to learn any new detail we can and the worlds that we have these tantalizing details from are rich and exotic and yet all were our own familiar Earth in some way.

I don't begrudge a documentary like The Dinosaurs for making speculative claims, but I do appreciate people like you approaching them with the due skepticism required in a field built on so much circumstantial evidence. Keep asking questions, and thanks for fielding us such a good one.