#14 is considered one of the greatest plot-holes…and it’s not. It’sacomplete misconception as to this beingamistake or plot convenience. “How did the T-rex get in and rescue them?” It’s not even theoretically answerable. It’s literally shown in the film. You can see very clearly earlier and even in the scene itself that the visitors center has an incomplete wall in the background that’s only covered byasheet of plastic. That’s how the Rex got in. As to why they didn’t hear it coming? Well…I’m pretty sure you’d be focused on the raptors about the kill you too. Besides, just old fashioned movie suspense tactic.