It says "any third party".
It is also part of a list of 'or' options. You can abide by one of the other options and not need to adhere to this one.
Yes, it’s one of a list of alternatives. The GPLv1 and GPLv2 sole applicable alternative to the written offer is to send the source code together with the compiled code; i.e. to all customers, in the box. Which they presumably didn’t do, so I don’t know why you bring it up.
(GPLv3 adds the allowable alternative to point to a web page or similar where the source code may be downloaded. I.e. you don’t have to waste money by shipping a CD, you can just print the URL on a note or in the manual. But this was the GPLv2, not v3, so it’s not applicable here, nor has anyone said that any such URL was provided.)
My point is that the op commented:
> No part of the GPL, as far as I'm aware, requires distribution to anyone who isn't a customer.
...and I am agreeing to this position, against fuzzyh. Specifically "anyone" != "any third party" != "any third party... unless you've abided by a) or b), which don't require distribution to 'anyone' either."
That’s correct, in case they actually ship the source code with the hardware, they’re complying. I very much doubt they do that. As such, option b) comes into play.
The GPL FAQ is very clear on the point that "any third party" means exactly that: Anyone that gets a hold of the offer (which you’re required to provide, otherwise probably also a violation) can request the source code.