I don't entirely dismiss it, either, though the examples the GI gives for the Doctor being blood-soaked do actually all refer to events that already happened and the audience is familiar with. Leader of the Sycorax = The Christmas Invasion, Solomon the Trader = episode 7.02, the Cybermen (take your pick, most recently just in the previous episode) and the Daleks (again, take your pick). That none of these events are actually the Doctor going on a killing rampage doesn't exactly speak of the G.I. having information of the Doctor doing atrocities in the future. Or wouldn't he have alluded to them instead (a la River asking Ten, when she meets him, about "the wreck of the Byzantium", which the Doctor and the viewers alike had no clue yet about but would understand in the fifth season)? Nor does it speak of him giving a reasonable assessment. (I mean, when the Doctor is accused of misdeeds in The Christmas Invasion, people usually name Harriet Smith, not duelling with and killing the Leader of the Sycorax. And killing Solomon the Trader more recently did cause criticism in some reviews I've seen, but it was also presented as something for which the alternative would have been to let Solomon cause the deaths of thousands and a war and continue with his slave trade. Etc.) I mean, seriously, if you want to come up with Doctor misdeeds (and limit yourself to New Who for Doylist reasons, i.e. not wanting part of the audience to go ???), and want the audience to believe the character who names them is onto something, as opposed to taking rubbish, there are really far better examples. Why not bring up the Family of Blood, for starters?