1 It seems odd to have such a clever callback to an earlier arc and then not to have it mentioned in the episode at all.  

2

Sato has done a lot of hinting in this series, as a way of avoiding unnecessary exposition. For instance:

When the Hakuoh Pirates raided the Princess Apricot, the captain of the cruise liner made a joke about the Bentenmaru's crew being in quarantine. How did he know that?

Well, later, his first officer delivered a bag full of goodies to Marika and mentioned that Show, the insurance agent, had asked them to do it. Why would Show have them do that? As part of a briefing to the captain of Princess Apricot to let him know that Bentenmaru's raid that day wasn't going to be normal.

Likewise, in ep 25 we see the captains all sharing the special desert together. That was a callback to Marika telling the cook back home she wanted to do that. But the lady captain's last question about who should command the mission makes clear that it had been a working dinner. Marika had spent a lot of time laying out ideas for how to fight, and how they could win. We didn't see any of that, but we can infer that it took place.

Sato doesn't think he needs to paint everything on the wall.

3 They probably should have called it out directly, but at the same time, they were a little pressed for time there at the end. 

It does fit all of the information we have, though, quite nicely.

4 Also, some of the exposition may have been lost in translation.  I've noticed a few times where the name of a ship is spoken by the character, but does not appear in the subtitles.  I assume this is necessary in cases where the original spoken Japanese took less than time than the translators thought the corresponding English text could be read by the audience.   Thus some of what Steven has deduced may have been mentioned in the Japanese version.

It's almost enough to make me start taking Japanese lessons, just so I don't miss anything...almost.

5

You can't do a literal translation. There are all kinds of ways in which that doesn't work.

For one thing, idioms. You can't translate idioms literally; they don't make sense.

Another problem, when it comes to Japanese, is that Japanese grammar doesn't require you to make complete sentences. You can leave out parts of speech if they can be filled in by the listener. But sometimes the translator makes a mistake in filling in the missing pieces. There's one in Strike Witches 2 like that which bugs me every time I watch it. At one point Yeager is trying to distract a neuroi to make it ignore Lucchini and Miyafuji. Suddenly the neuroi turns and starts shooting at them. Yeager says something that would literally translate as "spotted!"

The translator made it "They spotted me!" But she was already known. It should have been "Spotted them!" referring to Lucchini and Miyafuji.

There are also cultural things which don't translate, and lots of other issues. Translation is as much art as science.