Zero-Zero Ejections – Can they all do it?

I heard recently that a privately owned L-39 Albatross was involved in accident (sometime earlier this month) in England. The plane apparently suffered brake failure and exited the end of the runway onto a main road / motorway.
The pilot ejected from the aircraft but was killed when his chute failed to deploy. This suprised me, as I figured the L-39 should have been modern enough to warrant the standard installation of an ejector seat capable of zero-zero firing.
Either the seat malfunctioned, or it simply couldn’t work at this altitude. This leads to my question. Does anyone know why an ejector seat for this aircraft would “fail” to save the pilot, and is this similar to other Russian aircraft?

What is the status on British civilians owning live ejector seats?