Yeah, retry time is quicker on Disruptron which also makes it easier. Dark Animus had higher personal responsibility than Lei Shen, for example, but a weaker dps check and less coordination. Quick attempts were part of the reason why nearly everyone considers DA easier. Regardless, the first kills of Disruptron took fewer than the 200-300 attempts the first heroic Lei Shen kills took.
Group bosses (even DA for instance) will naturally take more attempts than solo trials to complete, at least from what my (and most others') experience shows.
However on the flip side Lei Shen is not "light" on personal responsibility either (as Daught mentioned above); far far from it. Each player is pretty much taxed (until the fight is outgeared) at some point at least and a single mistake from a player would generally be a wipe. Sometimes the reason you didn't wipe the raid was because someone else wiped it before you could!
And to reiterate (again) ad nauseum, I still believe comparing the two is apples and oranges.