> Conference probably had a hotel block they were booking and a link to book so you know which hotel to camp.

In this case it was Hilton. And if the CEO stayed at Hilton he had no reason to be on the street outside the hotel where the killer was waiting for him. Somehow the shooter knew that the target is not staying at the Hilton and will be walking to the front entrance. BTW, the normal practice for high profile individuals to arrive in a car to a service entrance hidden from the public.