The way the NBA league pass games are broadcast, nothing is sent to the receiver until the broadcast actually starts. The splash screen is just from the receiver software. Nothing is sent after the broadcast ends, either.
When they first launched the channels, if you accidently recorded one of the channels before the broadcast started or after it ended, it would screw the recording up, listing the recording as a ridiculous long time (like 143 hours or something) and starting over if you tried to do anything but play it from the beginning straight through.
Obviously, that really sucked, so they fixed the problem by making it so that the receiver refuses to even try to record the channel if it's not getting a broadcast for the channel. Hence the lack of start early and end late options.
The league pass channels (not the NBA TV channel) don't schedule more than one game on the same day. They also have a hugely long broadcast time listed, which is usually 3-4 hours too long. During that time, your receiver will pretend it's still recording (if you don't manually stop it), but once it's over the recorded time is how long the broadcast actually lasted and the no-signal part of it doesn't actually record anything.
The worst part is that you can't effectively use the bonus name-based recording options to get your favorite NBA team's games, because the NBA League Pass channels always have a couple of "Team vs. Team Coming soon" guide listings that will block your tuner schedule if you key off the team's name.