See, BenRG, you take it as ridiculous that Ross would have seen Jurassic Park, I take it as evidence he at least saw it himself before declaring it ungodly. Whether he's making the reference intentionally, that's actually up for some debate, because it's not necessarily just a reference; it's a full, logical statement, considering Dina has just outwitted him. It's probably a reference, but it might not be one he's making consciously.
Either way, it's happened, it's canonical, and it's pretty obviously a matter of pacing out the strip and giving Becky the chance of getting to the fountain. I agree with your point about Dina; I don't see her coming out of this unscathed, though I don't know if her injuries will be nearly fatal.
Any case, it appears the gun is out of his grasp, which is a good sign.