Maybe if he hadn't done it Hill would have scored, and maybe he had little choice because as he went in to tackle Hill, Hill gave him a stiff arm that changed how he could tackle him, but Poole first appeared to come close to face masking him, and as Hill pushed him away, Poole horse collared him. It seemed like a dirty tackle all around to me.
https://twitter.com/Saints/status/1043948260992286720