Ambassador Brigety appeared to refer to a previously known episode, when the Lady R, a cargo vessel under western sanctions flying a Russian flag, docked at South Africa’s largest naval base.

Source: https://www.eyeradio.org/us-ambassador-accuses-south-africa-of-supplying-arms-to-russia/

Mr Unga said demonstrators seen waving the Russian flag in Niger's capital, Niamey, since the president's ousting may point to Wagner Group involvement.

Source: https://www.express.co.uk/news/world/1798296/wager-group-niger-coup-role

Seems that he just stopped next to someone holding a Russian flag to pose for a quick pic, and then continued on his way.

Source: https://japantoday.com/category/sports/ukraine-urges-australian-open-to-ban-djokovic%27s-father

The EU said that the ban will also apply to vessels that try to evade the sanctions by changing their Russian flag or registration to that of another state.

Source: https://www.blueprint.ng/eus-new-wave-of-sanctions-target-russias-middle-east-shipping-coy-2/