The situation is this:
TIE Bomber has a Target Lock on an X-Wing. The TIE Bomber has equipped Deadeye and Proton Torpedoes.
During the round, the TIE Bomber gets a Focus token. The X-Wing evades the bomber's firing arc, but a Y-Wing is in arc and at the right range for the torpedoes.
The Proton Torpedoes card says:
"Attack (Target Lock): Spend your target lock and discard this card to attack."
The Deadeye card says:
"You may treat the Attack (Target Lock): header as Attack (Focus):
When an attack instructs you to spend a target lock, you may instead spend a focus token"
The TIE Bomber player decides to use only the first paragraph of the Deadeye card in order to remove the requirement of having a target lock on the defender. Because the second paragraph has a "may" in it, it is optional and he decides not to use it.
So he uses his focus token to target the Y-Wing, but decides to discard his target lock instead of discarding the focus token. The target lock was on the X-Wing, but the proton torpedoes doesn't demand it to be on the defender.
He spends his focus token to modify his roll.
Is the TIE Bomber player following the rules as written?