Crowe and Frost died from friendly fire. Spunkmeyer is thought to have died in the drop ship explosion. While these deaths can be argued that they were caused by way of action from the aliens, they weren't direct deaths. Vasquez, Hudson, Drake and even Gorman managed to take out several xeno either during combat and during their deaths. The alien that killed Ferro died as a result so this is balanced. Dietrich, Apone and Wierzbowski are the only ones that were killed without taking any xeno with them that we know of. Hicks and Ripley also clocked up the kill count. There were more xeno casualties by marine fire then there were marine deaths by xenos despite having an overwhelming advantage.
