Here's a theory on why the show repeats 3 hours later (and this applies to many cable shows in general) --
Satellite providers offer only the East Coast feed of TBS (as far as I know). This means that, in satellite homes, the initial airing of Lopez Tonight is at 8pm Pacific Time. The program is designed to air right after broadcast primetime ends -- 11pm Eastern, 10pm Central (and this is how it's promoted.) In order to make this work in the Pacific Time Zone, the program repeats at 2pm Eastern, which is 11pm Pacific.
Viewers to TBS-HD, regardless of whether they have satellite or cable, have the same issue. There is no West Coast feed of TBS-HD.
Of course, as usual, none of this applies to viewers in the Mountain Time Zone. The program airs at either 9pm (right in the middle of broadcast prime) if you have satellite or are watching TBS-HD, or it airs at Midnight (two hours after broadcast prime ends) if you are watching the regular TBS on cable & your cable system takes the West Coast feed.
It sure would be nice if cable providers, particularly in the Mountain Time Zone, could "time shift" programming -- the way that local broadcasters do -- so that programs air in their intended time period(s).