Diplomacy time is probably the best option, yes, if venting the hangar fails. Venting is a good option, assuming Sadish can be saved somehow.
There's always a way
I mean, this is just the beginning--we're just discovering how gritty this context is!
...But nobody has tried humoring them yet though. Draig: Do you roll for most/all things?
Also I seriously did think the hangar was closed and requires authentication to open. :I
Chemical slugthrowers are stupidly difficult to detect, not without dumping enough x-ray radiation on the ship to sterilize most of the crew. A gun is really just a chunk of metal. Gunpowder (even a slightly nicer version of it) is unremarkable in the extreme. A shuttle is not a piece of luggage going through an airport scanner, nor can you even do a thermal sweep like you could against a ground installation (with varying levels of success).
If they'd been carrying energy weapons, had been using personal shields, or really been doing much else to generate any sort of electronic effect, you might have been able to get something from the Reunion's advertisements systems trying to pick out the equivalent of a cellphone, but they're all analog. (Because it's the cheapest way to get past scans)
This does also imply that the bomb is a relatively stable one, but also one that does not rely on electricity.
As for your hangar... They requested permission to dock, you granted it. I thought about whether you'd have to authenticate to let Mickaw out, but I figured that would really only slow things down and generate an unnecessary 'open the doors' action. Since Sadish went down to meet them personally, the assumption is that you let them onto your ship. After all, the alternative involves a lot of jumping and holding of breath- which typically doesn't work well in space.
...Now that I recall, Draig: We do have electronic warfare in our ship right? Give that our range to the hangar is...just already 'inside' our ship, can I do a quick scan and subtly affect stuff in there?
DigitalHellhound: Mind chatting Boris up with me? I can't wait to hear from Sadish (and Draig: DO we know what's going on in the hangar .-.)
Indeed you can. Machine guns, regrettably, aren't terribly hackable, but the idea is right. You can certainly attempt to break into their shuttle systems.
The drone was linked to the Reunion's comms, so yes, you have eyes and ears down there, and there are probably a couple of cameras down in the hangar from its days as a parking garage.