An expert is commonly one who is well read in his/her chosen field or avid hobby. That statement implies experience as well. I have heard it said that since most people don't read any concentrated amount in their area of knowledge. You can be an expert by reading an hour a day in your field for a year and a world renown expert with an hour a day for 5 years. I think this comes from Dale Carnegie but I would have got it second hand.
I don't see how if you are an expert you cannot use some jargon despite your efforts to make your article readable. An easy example would be the term SEO (search engine marketing). There are others too like SEM, SEF etc.
Therefore I would conclude but not with 100% certainty that an article made by someone who is far from an expert would lack any accurate use of industry jargon. Can you see an expert on butterflies calling them bugs?
Just my humble opinion.
And by the way, people can be experts but English may be their second language Tussin. Our school system doesn't encourage excellence in spelling or grammar. Proof reading isn't always done due to time and that is unfortunate as well. The use of profanity unless it is intrinsic to the work being written generally indicates that the writer lacks the skill to adequately express himself.