Well the test results for that EICR appear to be believable at first glance.
I'd say either the Zs or R1+R2 are calculated as they all have exactly the same difference, but this is permitted by the regulations (personally I don't agree with it, but it is perfectly acceptable)
What is surprising is the complete lack of any comment on an installation which is apparently 20 years old, you'd expect there to be something even if its just general wear and tear.
They haven't ticked the box for alterations/additions to the installation but that CU can't be more than a few years old (I'm pretty sure that CU wasn't even manufactured 10 years ago, let alone 20)
Id say on the balance of probability that EICR hasn't been carried out with the due care and attention that it should have been.