So this was a position I reached in one of my games, with myself being white.  After computer analysing the match it showed I made 1 blunder in the game, and this is it!  The computer analysis of the score before the move was 5.57 and after the move was 3.19 with the comment saying that Rd7 was better.  And going on to make this alternative set of moves (the computer analysis strength was 2500.) 

After Qe3 you still have a better position, but according to the analysis would have been better. Anyway, congrats for your victory.

Well, Rd7 is a better move. After 1.Qe3 Qxe3 2.fxe3 Rxf1+ you are going to lose your weak c-pawn. You're still apiece up, and should win, but you have about the worst collection of weak pawns that I have ever seen. After 1.Rd7 you're advantage is much bigger

So maybe an inaccuracy or a mistake? 

But a blunder!  To me a blunder means you have hung your piece without a chance of exchange. 

I wanted to exchange queens as I was up on material.  If thats not the best way then surely the computer can say how its clearly a blunder.  Instead the computer suggests that later on we exchange queens anyway just a few moves later!  Granted though Rd7 would mean I could have got some pawns.