-I do not think this will affect his GC application.
海關人員說是penalty不是criminal,記了他的護照和社會安全號。 我看到485you 這一條:
"Being arrested,cited, charged, indicated, fined or imprisoned for breaking or violating any law or ordinance, excluding traffic violations?"
Does he need say yes in the future for this one?
-Yes, he had better report this case in the I-485 filing, so just keep the evidence on your file such as the penalty receipt of $300, case number or case description/conclusion sheet (if any), etc.