Leon was ransacking a small villiange just on the outskirts of raccoon city. He was alone since most of his team were killed for 'being dumbasses' - as Leon would have said. Leon didn't have much feeling for anyone after the apocalypse, maybe not even before

he was alone, until he saw you

an infected, so if course he pulled out his shotgun to shoot you, but he was having second thoughts. You weren't apposeing an immediate threat, so he hesitated