Bury's actions and attitude towards the Moties

Question

In "A Mote in God's Eye", nearing the end of the book,

when the MacArthur was being abandoned and evacuated

Bury got hold of his "special" air-bottle:

Bury pushed and clawed his way toward the air-bottle locker. Ah. It was still there. He seized the dummy and handed it to Nabil, who fastened it to Bury's suit.

It is not stated clearly if he had two air-bottle on his back or one, but judging from what the officer said I understand that he didn't have additional air-bottles save the one "special" one:

"That won't be necessary, sir," an officer said.

The air-bottle contained something potentially very valuable to Bury.

The dummy bottle was on his shoulders, and inside it two miniatures in suspended animation. Wealth untold! Technology beyond anything even the First Empire ever had! An endless stream of new inventions and design improvements. Only. . . just what kind of djinn bottle had he opened?

But soon Bury had to throw that air-bottle in self defense (this also implies that he had only one, otherwise a better wording would be "ripping an air tank loose"):

He was wrenching at his back now, ripping the air tank loose. He poised the cylinder over his head, in both hands, and pitched it.

Once everything was settled, Bury thought this line:

Good: he'd thrown the right air tank. Allah was merciful.

This seems strange from a couple of reasons:

1. If he only had just one air-bottle (as I understand), why would he think about "the right air tank"? Didn't he have just the "special" one? And if he had two air-bottles, which one is "the right air tank" - the "special" one or the real one?
2. Was this the pivotal point of Bury's change of mind about the aliens? For the rest of the book his attitude is very different from before this incident, and I find his change of heart very sudden and un-genuine, as if he is hiding his true feelings regarding the aliens.

Basically I feel that I missed something vital regarding Bury around this incident, both in his behavior during the incident and how it has affected him later in the book. Perhaps "The Grasping Hand" is able to better clarify about Bury, but I haven't read it yet.

Answer 1

Bury had two air bottles; the real one that must have been attached to the suit already (the "wrong" one to throw) and the dummy one that Nabil attached on the way out (the "right" one to throw).

I don't think he had an instant change of heart about the wisdom of keeping the Moties; under the circumstances, he wouldn't have time. But he did know that if he threw the only tank that actually had air in it, he'd suffocate. Later on I believe he was indeed convinced that the Moties were too dangerous to allow out of their solar system, but right then he was just trying to stay alive.

If he had any other weapon to hand, he'd likely have used that instead.

Note that the full quote is:

He took a deep, shuddering breath. Good: he'd thrown the right air tank.

That is, it was only after he'd taken a deep breath, and found that the air was still fresh, that he was sure he had indeed thrown the right tank.

To address your other concerns:

• The officer's phrase "That won't be necessary" meant that a second air tank wouldn't be necessary, since it was only a short trip. Bury's reply was "One never knows".

• The phrasing "ripping the air tank loose" rather than "ripping an air tank loose" doesn't mean that there was only one air tank, but rather that it was a specific air tank. You would only say "an air tank" if he didn't care which one it was.

Answer 2

Bury saw what the watchmakers had done to the Macarthur, and realised the danger that they represented. He wasn't throwing the dummy air bottle at some threat in self defence; he was throwing it away because the threat was inside it. And he clearly must have had a second real air bottle as well. His realisation during the evacuation that the Moties were a threat rather than an opportunity is what changed his attitude; throwing away the bottle is the first effect of that, not the cause.