It should be noted that it was WD whose plants were hard hit by the floods, not Seagate or the others. WD was the one that had a relatively high concentration of plants in that area. Seagate's claim at the time, which is partly backed up by these numbers, is that demand on their side went up since WD could no longer fill the aggregate volume for HDDs. This is where the whole price-fixing conspiracy theory comes from. WD raised prices after the floods because they lost manufacturing capacity and needed to dissuade high volume purchasing just so they wouldn't themselves run out. Seagate, who lost little to no manufacturing capacity, raised prices to also dissuade high volume purchasing as they tried to fill in the slack left by WD. They ramped up their own production to take advantage.
At this point you wont see Seagate's prices drop until WD's prices drop. It actually makes a lot of sense for us as consumers to endure it this way. The alternative is that Seagate drops it prices to where they probably should be, and WD dies as a company from being unable to match Seagate's price. Don't pay too much attention to Seagate's numbers. Look at the overall total quarterly shipments of HDDs, and the average price. But, no one is probably going to listen to me, or do the investigating themselves, so I'll probably get down voted to oblivion for "defending" Seagate ad WD. Oh well.