 Primary sources are unclear on which detachment Washington led; the other was led by Lieutenant Colonel George Mercer.In the dimming light of early evening and the haze of musket smoke the two detachments mistook each other for the enemy; the friendly fire incident resulted in 40 casualties.Washington claimed to have interceded, "knocking up with his sword the presented pieces", but Captain Thomas Bullitt, the only other officer to leave an account, held Washington responsible for the incident, noting that his opinion was shared by "several of the officers."