dont think that would happen becouse the ship dose not know of the temprol agents yet, and if they did they would have to get to the home worldby the time they did the Agent would have assasinated him, also if they sent 2 agens, one from two difrents worlds they would have a better chance. then you ahve the thing we saw in First Contact, were earth was a similated but the enterpize was not...therfor if the agent was in the past there is a chance he would not be afected.
But what if he found out about temporal investigation. or removed it from time becasue temporal investigations doesn't know about him