The engineers don't give a damn about a Munro PR video about a competitor, period. It's a complete non-issue for them, and the same goes for their managers who are the ones who decide to work with Munro. They want to know every detail about how all the sausage is made (or what the sausage actually is). They don't care if the car is well made or poorly made; they're focused on the how; after all, even a car with severe quality control issues can offer useful insights. Besides, every peculiar (or even dumb) design or manufacturing decision they've made was previously laid bare by companies like Munro. Think of the process as something more like peer review or a morbidity and mortality conference for doctors. It's not a public process, despite something like this video.
Basically, the people who would care if Munro upset the company by speaking favorably about Tesla are the people who have no involvement in whether their company works with Munro in the first place. If someone from Ford marketing told Ford engineering to quit working with Munro because of a video, they'd be laughed at and promptly ignored.