Back at Government House, the Argentine commandos' pressure continued. There is some evidence that their use of stun grenades, mistaken as high-explosive rifle-grenades and/or mortars, and their continuous shift of firing positions during the battle led the Royal Marines inside to believe they were facing a large company of marines and were hopelessly outnumbered. Actually, after the failure of Giachino's small platoon to break into the residence, the British were surrounded by only a dozen amphibious commandos. These men were under Lieutenant Lugo, Giachino's second-in-command. The Land Rovers used by the Royal Marines were disabled by automatic gunfire from the commandos.