Other than the this talks about the 190A in general terms (it's like saying in general Spitfire, when the Mk1 is completely different to the XIV), you have to look at this in greater context. If I remember rightly the 190 used in that test was a used and slightly abused (tested by the British for some time) A4 that was accidentally landed in the UK. The P51B/C/D in reality faced the A6 initially and then A8s and occasionally D9s. It's highly unlikely a P51 ever encountered an A3 or A4 in combat other than RAF ones which flew over to Norway where the groups there had the older aircraft.
Sources for WW2 fighter performance is a bit of a dark place when it comes to captured aircraft - sometimes the fuel was wrong, the aircraft was old and lacked spare parts or in one case of a D9 that ended up in the US, it had the wrong wings attached to it. It's best to look at all sources before drawing conclusions.
I would suggest reading Johannes Steinhoff's "The Final Hours". He paints a very vivid picture about the state of the Luftwaffe in 1944/45. In his opinion at least - and it's quite a well respected one - it was nearly impossible to compare combat performance between aircraft anyway after 1943 because of the imbalance of numbers.