Not defending Isuzu.....just stating fact that had the oil level been maintained.....Oil levels shouldn't have needed to be checked so often on newer engines in the first place. Not all the Isuzu engines that expired took this many years to happen. (And not all engines that expired had a lot of mileage on them either, but since rjonchan hasn't stated the mileage on his engine at the time it gave up the ghost, his case is impossible to classify at the moment).
And it was a design flaw (or actually, a combination of flawed engine control systems) that caused the problems in the first place. Otherwise, Isuzu would have just kept putting the same piston rings back in as were originally used, and people wouldn't have started jury-rigging their EGR systems.
You're of course free to defend Isuzu about this specific issue if you want, but I've personally read too many stories on this site about owners who were pretty much left hung out to dry by Isuzu in cases like rjonchan's. That's not saying all owners who had this happen were, or that everyone at Isuzu should be grouped into the same category, but the powers that be at the time could have handled more of these occurences better than they actually did.
I mean, didn't it actually get to the point that there a class-action petition towards Isuzu being circulated years back regarding issues such as this? That type of thing doesn't usually happen because everyone is satisfied with the service they've received, or that should have been reasonably expected.