This is why I'm not a fan of using Maintenance Plans.  I much prefer to code all the jobs myself so I get detailed output.  When I'm in DBA mode (I'm currently doing SQL development) I use ISQL to run my DBCCs and pipe the output to a text file.  It's run as a batch file that keeps 10 days of logs so I can review older runs in case I missed something.

Basically the batch file would do the following steps on every database every night (we didn't have terrabyte data stores):

dbcc checkdb

dbcc newalloc

dbcc checkcatalog

We originally also did checktable(syslogs) but that was turned off for 2000.

The advantage of the text file was that it gave you detail including full error messages.

But that's just me.

As far as what happened to you, I don't know.  SQL Server can fix simple problems itself, that's the whole purpose for DBCCs.  A lot of errors are transient, i.e. they show up on one run and are gone on the next.  So if the error doesn't repeat, I wouldn't worry about it.  The important thing is to look up the error message online and make sure it isn't one of the important ones.  Consistency errors like what you got are generally not a problem and the DBCC handles it.

I really like SQL 2K compared to older versions because I would almost never see errors in my DBCC logs.