I have encountered this phenonomen and it is actually quite a versatile.
The first example, I would call that deliberate and intentional misinformation. I am a member in our local LBGT online portal and one of my friends from neighbouring country told me about one "strange" person, who had recently joined. She labelled herself a MtF transgender, but when I started with my usual opening remarks, I instantly got a lot of BS in response. For example, she claimed to have been 1/2 boy and 1/2 girl ever since childhood and that this had been officially recognised as she allegedly had female gender marker in her passport (to someone who is very familiar with our administrative system - this was the first big warning, because those people dont care how You look or feel like - what is between Your legs and in Your birth certificate - its all that matters to them). She also turned out to be totally unaware what being an IS condition means, so... Next, she tried to convince me that she always had bewbs ever since her teen years. Yet, my other friend, who was also exchanging PMs with her, told me another story - that person told her that she had been on contraceptive pills for one year and so her bewbs grew out - which is another BS, of course.
The final straw was then this girl just replied me with a sort of attitude "If You have any questions about transitioning - I will gladly teach You how...". Well, no thanks, I have no idea what You are doing over there, but I dont want any advices from You.
Another example is unintentional misinformation just to show off Yourself. I have encountered a lot of older transpeople, who have not tried most of the things they claim to be experts at, but who will tell You a lot of cons why You should not be trying this and why X is better than Y (that particular example was about IPL vs. laser). Also, the exaggerated use of "natural" hormones vs. "estradiol and AAs" - "that thing really works because not only my bewbs, but my butt was itching too". Seriously? Your butt??? WTF??? It just grows extra fat around hips and there nothing that could be itching, lol.
Seriously, these people do a lot of damage, especially, when facing younger wannabe transitioners, because that misinformation can be harmful.