Let's forget "Greatest pass ever" talk and look at it as maybe the "Greatest full court pass ever" in which I don't think you could even make that argument.
Watch Bird highlight real, and at about the 3 minute mark, Bird is scrambling for a loose ball, collects it, spins around and launches a one handed "foot ball" pass the length of the court, to the wing, with a defender back, and still manages to hit his man in stride (think it was Max, couldn't tell) who dishes to McHale for a quick 2. Off-balance, quick glance, full court pass. Most incredible thing I've ever seen.
Wade clearly had time to set himself and make that pass. Not to take away from it, it was definitely an incredible pass. But greatest ever? Naw, I wouldn't even call it the greatest full court ever.