"I heard from a guy...." or
"I read in another thread..."
is often someone's way of seeking clarification for new knowledge.
If it's relevant to the discussion it can be helpful (by being confirmed as correct by more experienced growers)
or be exposed as incorrect (which is also helpful).
If someone prefixes their post with such a warning, about the actual validity of the information,
I see no reason why it should cause annoyance.
It's a honest way of joining a discussion.
It's also how a newbie learns.
Most of the more experienced growers are extremely generous with their knowledge
and patient with a newbies misconceptions.
I do, however, take issue with the rare occasions when an experienced grower seems to resent a newbies inclusion in a thread.
This often happens when an experienced grower seems to feel they do not get the praise they deserve.
But the truly expert amongst us (DoubleJJ, Getawaymountain, Jondamon, Nuggbuckets,.....etc) are never dismissive or condescending to so called 'Newbies'.