Agreed. That fact that he's defensive from the off makes it clear all is not what it's cracked up to be in my book. I wouldn't even bother making an enquiry let alone take a look at the car if I was in the market...Yes it looks like the car was rejected before due to the HPI check etc.
Also the seller clearly has an attitude problem, with comments such as "Stupid offers will not be answered, so don't waste my time or yours". That is not the way to market and sell a car.