The waiter who served Russell his steak said it was as early as 9:50pm. This case has never been difficult to connect all the pieces together. The timeline is key because there is so much BS.
Waiter -
When asked, he says that on 3rd May he only remembers that one guest from the table left for about 10 minutes, given that when he was about to serve the respective plate he was told to hold the food back for a few minutes, and that it was about 15 minutes before the guest returned, at about 21.45.
So he is saying the guest returned about quarter to 10, he managed to eat most of his dinner so add another five minutes or so that's about 10 to 10 it could easily have been about 5 to 10 or even 10 when Kate came back.
Gerry then went to the apartment to search it again, then he went outside to test the blind, how long would that take? Then he was seen searching around the pool area, he couldn't possibly have been the person the Smith family saw at 10 o'clock.