Ash was watching out for enemies and so was Horizon, until they started fighting with each other.

Horizon: “you better keep your mouth shut, you are nothing close to perfect or perfection.” Horizon hisses at Ash.

The simulacrum woman rolls her ‘eyes’ before pointing her gun at Horizon.

Ash: “you know nothing about perfection, Doctor Somers. I suggest you get back to watching your back before you compromise our position.”