A good 'ground CAT' question, perhaps?
Incidentally, AIC 107/2007 (Yellow 252) gives a good summary of the UK sitch regarding climb and descent rates in CAS. If you are registered on the appropriate website, you can download it from
http://www.nats-uk.ead-it.com/aip/cu...7_Y_107_en.pdf .
If the Hawk was in UK CAS and cleared to FL300, it should have been reducing its climb rate to 1500ft/min or less from FL285 onwards. Easy way to remember is 1000/1000 - a vertical rate of no more than 1000 ft/min within 1000 ft of the cleared altitude or level.
Oh to still fly something which can climb at 1500 ft/min, let alone 6000 ft/min!