Nah its because he cant judge whether hes mutated or not
But he shot others immediately
Cause he knows that everyone he shot were already infected , example is the nice guy who helped mushroom, he shot him since he saw that small dot of wound in his hand, A fucking ant bite
Actually kind of...he spared him because he judged that even if he was a xenogenic, he was harmless with low to no chance of infecting others. Since there's a very very low chance that he could be wrong about him being a xenogenic, he took him for genetic testing instead of shooting the harmless little mushroom
Did he spare him just cause he’s cute