Sure, it's possible someone could memorize a bunch of jargon and convincingly pull a Jarod with it, but I've never found that convinces anyone other than HR. To use the jargon grammatically and idiomatically you need to have grasped the underlying structure.
I agree, and as someone that's taught students you know when they really do not understand the underlying concept of a word. I've seen students use nouns as verbs and try and turn nouns into verbs when writing science. From experience I would say that before once can communicate science, everyone needs to understand the nature of words. If I want to talk to you about the effects of black holes, you need to associate the properties of black holes with the word.
I try not to be exclusionary, though. Someone can not know the jargon and still have a good idea.
Having been at University for 8 years with undergraduate and postgraduate studies, you meet foreign students that do not grasp English fully, but they know their stuff. I worked with a Turkish student, and while he struggled with spoken English, his written work was very good. It took him longer than others to write, but his technical writing was excellent.
What they can't do is skimp on the terminology -- if it isn't correct, it isn't exact, and if it isn't exact, then you have no idea what the person is really thinking.
I feel that is the case here. Reading back through the thread, the lack of understanding the jargon and mathematical concepts showed. There was back peddling, changing the goal posts as he began to understand more, there were even times when you felt he understood the concepts and introduced his understanding to move the goalposts or changed his angle. Never once did he say 'OK, I see that now.' I felt stuck on base 1, on occasions moved to base 2, only to find myself back at base 1.
