the only reason you could have possibly had legitimate speed that high would have been due sprint not wanting ANY complaints with thier flagship phone. esp since it's web based.
(kinda like how m$ vista pages are faster than the XP pages)
due to the nature of cdma data you download is actually a broadcast stream with certain time slots allotted to your connection. it's possible they bumped the priority for the pre's temporarily. otherwise it was a bad test. (burst speed)
http://en.wikipedia.org/wiki/EVDO