It often reads like a unspoken backhanded way to call into question or place doubt on the object being discussed without providing supporting evidence.
For instance, "a number of people agree the trim tag rivets look legit, but there are generally accepted exceptions such as..." then listing the known exceptions to support the observation.
If someone just wants to stir the post by casting doubt, they might say something like "those look just like rivets in that trim tag" (not that I'm saying anything negative), but I'm just saying....(the rivets don't look legitimate to get a rise out of other people)
It can sometimes be just a cowardly way of saying "it could have happened" with nothing of substance to back it up.
