A very similar exchange happened in Syria in 2018.

According to sources in Wagner, cited by news media as well as the Department of Defense, U.S. forces were in constant contact with the official Russian liaison officer posted in Deir ez-Zor throughout the engagement, and only opened fire after they had received assurances that no regular Russian troops were in action or at risk. The clashes lasted four hours and saw more than 100 Syrian pro-government fighters killed, with one SDF fighter injured, according to the coalition. No U.S. troops were reported killed or wounded.