I agree that the dice roller has issues. I needed 7 rolls to succeed, 5 at 7+, so 50/50 odds. It took 17 rolls to get 5 rolls of 7 or better.
Counterpoint: several people's character creation rolls.
What the forum dice roller does (aside from occasionally hang up and never resolve the page), is it strings together results at the relatively far ends of the spectrum. So normally you might notice a distribution similar to:
2, 3, 3, 5, 7, 7, 7, 7, 9, 10, 12
What we actually GET is closer to:
2, 3, 3, 3, 5, 7, 9, 10, 11, 11, 12
(Exaggerated somewhat for dramatic effect, but years ago one of our players, Brent, did a ~5000-roll test after getting mad about the dice roller, and this was the conclusion. Middle rolls are underrepresented, extreme ends are overrepresented, and like results tend to string together to a higher degree than one would normally expect.)
Note that both of them end up with a roughly average result of ~7. Which on a 2d6 is expected. But what the forum roller does is avoids the middle (more often) and gives clustering on both extremes. It additionally tends to generate strings to one extreme or the other, so if you've rolled a 4, your next roll is more
likely to be something like a 2-7...but once you've broken that cluster and moved up to a 9, your next roll is more likely to be a 7-12. This does perhaps cancel out on a large enough sample size, but one a sample size large enough to test, and with what we have available, it is what it is.