Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Although there is no disputing the impact that Steven Spielberg's Jurassic Park had when it was released in 1992, there has always been one scene that has bugged/perplexed me.  I speak of the climax, when Alan Grant et al are surrounded by the Velociraptors and about to be pounced upon, when suddenly the T-Rex lunges in and 'saves the day'.  It has already been established earlier on the film that the T-Rex telegraphs its approach with thunderous footsteps, and I'm pretty sure that even if the humans were surrounded by malevolent reptiles, they would notice a huge T-rex squeezing in through the front door of the reception center.  Possible explanations include the T-Rex's ambushing skills (as evident in the earlier Gallimimus chasing scene), the afore-mentioned distraction of the Velociraptors, or even a huge suspension of disbelief to better serve the dynamism of the scene.   I don't like the idea of T-Rex just being shoehorned into the scene to add some va va voom, so is there a better explanation?
Where did the T-Rex come from?

In Never Back Down, I don't understand the relationship between Max Cooperman and Ryan McCarthy.  At the beginning of the film scene they appear to be on good terms   Ryan is observing the fight Jake interrupts Max and Ryan are very friendly at the party   However later in the film he becomes friends with Jake and the rivalry develops   He sees (and presumably knows) Ryan beat up Jake in the bathroom He's aware of the rivalry and Ryan's determination He knows of the friction with Baja/Ryan/Jake   Knowing this why would he agree to join Ryan at his house (leading to his hospitalisation)? It he being naive or is this simply being used to tell the story?
Are Max Cooperman and Ryan McCarthy friends in Never Back Down?

In Spider-Man: Into the Spider-Verse, we learn that Kingpin wants to find a replacement for his wife Vanessa and son Richard by using their DNA in the machine that opens holes into other universes. (He uses a hair from a comb that gets put into the machine.)  But when Peter Parker as Spider-Man is fighting during the machine power up his head is pushed into the beam, which I assume was the reason why other spideys were pulled here because they share the same (close enough) DNA. Including Peni Parker (which could be a distant future relative in her universe, and even Spider-Ham (Peter Porker, which I'll accept as being close enough in his animal universe).  But as far as Gwen, Spider-Woman, how was she pulled into Mile's universe?  We learn that her Peter Parker was killed long before, so why did a portal/hole open up near her? When she would not share any DNA with Peter at all?  It can't just be the randomness we see from other universes, because we would have to assume there would be other (normal) people pulled in as well, not just spideys.  Maybe I missed something, but it just seems like they glossed over a valid reason.

How was Gwen pulled into Miles's universe?