Watching JP again (surprise surprise) and I just wanted to say that the film's representation of Lex and Tim are really great and still stand as some of the best kid characters in an action/adventure film. Not because of any character depth or super "grounded-ness", but in how the actors are portrayed.
The film does a great job at making the kids and their trauma feel believable. Lex's lasting shock of being abandoned by Gennaro, Tim's first words when Grant finds him in the wreck being "I threw up". Those are precisely how kids behave -- they often don't look at the big picture and stress disproportionately about what's right in front of them; the short term. Grant's reassuring Lex "That's not what I'm gonna do" and Tim "Don't worry, I won't tell anyone you threw up" are great little injections of Grant's transformation into something of a father figure while also adding believability to the children's characters.
Their ability to switch from humorous squabbling siblings to completely terrified, screaming kids -- it's all done really, really well.
Just wanted to write about this as I'm watching JP for the umpteenth time