Re: Did he actually filibuster it?
In the context of Rand Paul's usage, it is a way of running down the clock.
Those that hold the majority within the senate are allegedly in favour of the bill going through, so the only way to prevent it is to stop it from reaching the vote.
The bill can't be voted upon while senate discussion is ongoing.
As I understand it, the rules explicitly permit a speaker to have their entire point of view heard, no matter how long it takes.
So as the parliamentary session is of limited duration, if Rand Paul is able to tie up all of the remaining available time, the senate will not get to put the bill to the vote during this session.
With provisions within the Patriot Act about to expire, if the vote is not taken, the expiry will drop them from the act, requiring another run through the parliament to get them re-instated.
Lather, rinse, repeat for long enough, and the Patriot Act can be de-fanged to some degree, with no further additions for an indefinite period.
(All usual disclaimers apply. IANAL, don't play one on TV, not a politician etc.)