it's a classic troll technique. It's not independent of the other trollish tendencies. Alone, saying those things does not imply troll, but in the presence of other troll-content it is used to raise perceived standing and lower the probability that they are a troll.

EDIT: and yes, trollish opinions without trollish disclaimers raise probability of plain old stupidity.

EDIT2: Have to be very careful with understanding the causality of evidence supplied by hostile agents. What Evidence Filtered Evidence and so on,