Eh, I get your frustration, and I probably shouldn't say anything more because I know absolutely zero about the martial arts world ... but in the worlds I do know, in situations where there's a chance of injury, it's always best to observe someone and start slow if you didn't train them yourself. In the yoga world, it's amazing (and very sad and frustrating) how often you'll see people with RYT200 or even 500 who don't even know the first thing about hand placement - sending out masses of students at risk for shoulder injuries. Zen mind, beginner's mind, and all that

Anyway, sounds like you've been able to prove yourself - hope you get on well at this dojo from here out!