Obviously I'm speculating a bit, but I noticed this sentence in a recent article in The Age, about a death from the Eastern Brown Snake, in Australia:
"It is possibly the second-most venomous land snake in the world after the inland taipan, which is also an Australian snake."
Our article on the snake has this sentence: "The Eastern Brown Snake is the second most venomous land snake in the world after the Inland Taipan.[1] "
I wonder if the principle here is that if you don't want to admit you're sourcing from Wikipedia, you just add "possibly" :) Even when, interestingly enough, we actually had a source for that sentence: Steve Irwin's website :)
Steve