I've tried during the night and day.. but no where do I get an option to have someone go stand out in front of boone so he can shoot them.

Is this a bug or am I just missing the obvious?

It's in the form of dialogue - you should be able to tell them there is something in front of the dinosaur that you want them to see.

I think it also has to be during his shift (night).

yeah I guess it's a bug.. I got the bill of sale but still don't see that option anywhere.. thanks though.. tried it at night as well

Not just at night but at night and when he goes on duty,make sure hes up there at his post.

NM.. i got it.. guess it wasn't late enough at night the other times I tried.. found her house and had the option this time.. thanks a lot

You have to wait for two things: 1) Boone must be in the t-rex, and 2) she has to leave the hotel lobby. Once she's outside, the dialog option opens up. I think this happened at about 11:00 pm.