Ok, so here we have the USS Enterprise making an ill-advised warp jump, and now, because of engine imbalance, the ship cannot fire its phasers.
It plays out well enough for dramatic purposes that Decker countermands Kirk's order to fire phasers at the looming asteroid, and then explains his actions later.
But, what if the scene were played out like this?
Kirk: Mr. Chekov, stand by on phasers!
Decker: (wild eyed) No! Belay that phaser order!
(Kirk is stunned by Decker's bold second guessing of his order.)
Ok, the scene plays out to its conclusion, and Kirk says he'd like to speak to Decker in his quarters.
Cut to Kirk's quarters:
Kirk: Alright, explanation! Why was my phaser order countermanded?!
Decker: Permission to speak freely ,sir?
Kirk: Granted.
Decker: For starters, the Enterprise redesign increases phaser power by channeling it through the main engines. When they went into anti-matter imbalance, the phasers were automatically cut off.
Kirk: Then you acted--
Decker: I'm not finished, sir.
(Kirk looks at Decker with an "I will only indulge so far" expression)
Decker: Even if the engines were not the problem, we were still traveling at faster than light speed. The phasers would have blown up the bow, and then the asteroid would've finished us off, you idiot!

It plays out well enough for dramatic purposes that Decker countermands Kirk's order to fire phasers at the looming asteroid, and then explains his actions later.
But, what if the scene were played out like this?
Kirk: Mr. Chekov, stand by on phasers!
Decker: (wild eyed) No! Belay that phaser order!
(Kirk is stunned by Decker's bold second guessing of his order.)
Ok, the scene plays out to its conclusion, and Kirk says he'd like to speak to Decker in his quarters.
Cut to Kirk's quarters:
Kirk: Alright, explanation! Why was my phaser order countermanded?!
Decker: Permission to speak freely ,sir?
Kirk: Granted.
Decker: For starters, the Enterprise redesign increases phaser power by channeling it through the main engines. When they went into anti-matter imbalance, the phasers were automatically cut off.
Kirk: Then you acted--
Decker: I'm not finished, sir.
(Kirk looks at Decker with an "I will only indulge so far" expression)
Decker: Even if the engines were not the problem, we were still traveling at faster than light speed. The phasers would have blown up the bow, and then the asteroid would've finished us off, you idiot!
