This video shows that you have to pay attention well before the race start. The camera is onboard the WRR Radical SR3, which qualified 6th in this NASA Texas race at MSR Houston. Ahead is a white Porsche Cayman, which qualified 5th. Because pole at MSR Houston (clockwise) is on the right (inside), all cars qualifying in odd positions (3rd, 5th, 7th etc) must line up on the right side of the grid. But the Cayman is far left at the end of the Carousel, which prevents the car behind from lining up correctly. The result is that the cars are not in 2 x 2 formation entering the pit straight headed toward the starter's stand. The starter correctly calls off the start.
In NASA racing there is no splitter, so you have to know what your grid position is and how it defines the side of the track you need to be on. But even if there is a splitter, it is a good idea to determine your starting position before going to the false grid. You can, of course, figure out where you should be from the position of the car ahead of you on grid, since you need to be on the opposite side. But if you are confused, you may hinder the car ahead (SU Camaro in this case) from pulling into his or her correct position, as the Cayman does here. It took him too long to correct the mistake once he realizes the Camaro needs to be on the left.
The result is a shortened race if the starter makes the right call, as happens here. That's effectively bad sportsmanship. If the starter misses the problem and waves the green flag, the result is at best an unfair advantage over the cars behind and the risk of a protest for the errant driver. Worst case, the result is confusion and a crash.