The Loftus Road outfit had been in pole position to secure the former Celtic striker's signature, but were gazumped by a late move from Premier League side Norwich City
Norwich City announced the signing of the Englishman from Celtic on Friday, having made a late dash for his signature when QPR had appeared favourites.
And Redknapp has acknowledged that the London club were too slow in trying to seal a deal for a player he insists wanted to move to Loftus Road.
|6/1||QPR are 6/1 with BetVictor to win the Championship
"Deals have got to be done quickly and it dragged on probably two-and-a-half months altogether that deal. It was miles too long.
"If we're after a player and we really want him and he wants to come. Because the boy wanted to come, I don't care what anybody says, he was coming to us, but I just think that it seemed to be a bit of a mix up with the deal and everything. Never mind that's how it goes."
Redknapp has already made three additions to his squad in the close-season as he attempts to strengthen ahead of QPR beginning their push for an instant return to the Premier League.
Danny Simpson, Richard Dunne and Karl Henry have already arrived at the club, though the likes of Julio Cesar, Loic Remy and Adel Taarabt are widely expected to depart.