Hmm. I may be incorrect, but it seems to me…

[spoiler]… that there is only one circumstance in which the third logician may answer with certainty, and that is if both of the hats of the first two logicians are blue. Both blue hats must be removed from the pool for her to be sure that hers is red.

I make the assumption that the logicians have drawn their hats randomly from the pool. Therefore, the probability that the first logician will select a blue hat is 2/5 (two blue hats out of five chances). That leaves one blue hat out of four (1/4). Thus, 2/5 x 1/4 = 2/20, which reduces to 1/10. So I arrive at my conclusion that the condition for a correct answer (in which both blue hats have been selected first) is 1/10[/spoiler].