The first round of reimbursement was because of the Skynet bug where NPCs would have game-breaking overpowered weapons that were never intended. Instead of figuring out exactly who might have been hit by these weapons, they simply refunded everyone during that time period.
The second round of reimbursement was because they found a second bug that was allowing NPCs to turn too quickly at low speed, which was why players were seeing Anacondas outmaneuver much smaller ships when this shouldn't have been possible. Instead of trying to figure out how much of an impact this might have had in any given case again they simply refunded everyone who was killed during that time period.
There's a big difference between predictable, measured risks based on what we know of NPC performance and bugs that break the game. FD has not generally given out refunds when players have taken risks or made mistakes that have turned out badly for them. They are, however, quite willing to reimburse players who die through no fault of their own as a result of game bugs. In the past this has been done on a case by case basis, for example, when players were griefed by station defences from their PD systems hitting the station, but in those cases you had to submit a specific ticket that was investigated. I did lost my Asp twice during that period and got one of them reimbursed as it was clearly a griefing exploit. For them to individually investigate the last month of ship losses to determine exactly when an NPC weapon bug or turn rate bug was the main cause of player death would take them far too long. It's much faster and easier to assume that if the NPCs ships were overpowered due to weapon or turn rate bugs that it wasn't a fair fight for commanders, hence the very welcome set of refunds.
Well said. +1 rep