Genestealer Phase Scenario

[Henshin1]

Hi guys, I was playing with my house mate the other day and we came across this weird situation we didn't know how to handle. I had 2 genestealers lined up in a corridor just afew spaces away from a terminator watching me in overwatch. It looked something like this below (sorry for the poor diagram)

____ | |_____
|G|G| | | |T| |
| | |


On my first move, the genestealer in front took a step forward, the terminator shot in overwatch and missed. In my second move I moved the genestealer diagonally forward into the corridor running perpendicular to the one I was in, and out of the Terminators line of sight. Then I started wondering.

The genestealer is no longer in line of sight. So the Terminator cannot shoot at it in overwatch. But does that mean he shoots at the genestealer in the back? or does overwatch not shoot at all because the genestealer is not in LOS after he made the move?

Similarly, if the Terminator had Command Points left at his disposal and the genestealer moved out of the terminators line of sight, can the terminator still use his command point to shoot at the genestealer in the back? Or is he unable to use his command point because the genestealer that made the action is no longer in his LOS.

Another question I have which im pretty sure I know the answer to but i'll still ask just to make sure. The genestealer was shot at after he made his first move and survived. Then he moved diagonally out of LOS, on the next move, and back into LOS the move after that. Assuming the Terminator does not shoot at the genestealer in the back. Does the terminator still have the sustained fire bonus on the first genestealer even though it made a move out of the terminators line of sight. The rule book says if the terminator uses his next action to shoot at the same target he has the bonus. So I assume he does get it, but I just thought I'd check up with this one.

Thanks for the help guys.