The piece of biltong that Epkeen chews never gets smaller. It also always has the same upturned end as it has when he puts a "new" one in his mouth.
When Ruby is attacked, Brian cuts his restraints with a large shard of glass from the window he just ran through. The window shattered into small fragments, as safety glass does, so no big piece would be available to do so.
When Ali shows Brian the second dead girl on the beach, a boom mike is reflected in his sunglasses.