I was speaking to a workmate a while back who'd been telling me that his Insignia engine had seized. He said he was told something had blocked the flow of oil in the engine. Said it had just been serviced. I think it was an 09 or 59 plate.
If you look on line, there are a few stories of Insignias with the 2.0 cdti engine that have shown a low oil pressure warning before seizing.
There are even one or two Insignias for sale on various sites needing new engines, that look otherwise in good order