In the encounter with the Bulgarian (33:00 to 33:45), when our men splash him with milk, the splash on his leather jacket changes and dis / reappears from shot to shot.
A young man with Down's Syndrome tells Adam and Paul he only has money for the bus and shows them some coins. People with disabilities in Ireland are given bus passes and do not require money for public transport.
When Adam is high on heroin and lying down on a street bench (1hr07), the closeup of his eye shows a partially dilated pupil. Heroin would cause the pupils to contract to pinpricks.