Today I've got my stock DS2072 scope and hooked it up to a home build pulse generator which surprised me!
It is bone stock and havent't entered any license codes yet. Having about 2050 trail minutes left, it clearly shows a much higher bandwidth than the claimed 70 MHz. I've measured a risetime of 1.646ns (50 Ohm terminated) which equates to a bandwidth of roughly 210 MHz. It looks like the higher bandwidth 'option' is also active during the trail period?
Is the option screen showing you a 200MHz option ?
Is the system info screen saying it is a DS2072 ?
When I got mine DS2072 there was a standard 4 ns rise time, so I guess Rigol is now giving it away on their 70MHz models, or they made a stupid mistake by configuring it wrongly.
Another possibility is that your scope has been altered by the dealer/seller.