You would think they'd get their story straight before they said anything. OTOH they may be having a problem with people running their mouths to the press who, from their POV, shouldn't be; and the media nowadays will put anything out there as soon as they get hold of it...
http://news.yahoo.com/s/ap/20110503/ap_on_re_us/us_bin_laden_us
I personally think it's quite plausible they really didn't know where bin Laden was until a short time ago.
Maria