So they knew. They had 3 or 4 days before the let go call to decide what to do. They had all my medical data.
There's a lot of reasons to think this is a long-shot:
(a) You're non-US and abroad, so the ADA doesn't apply to you
(b) You're probably a contractor and not an employee
(c) Even if it applies, the ADA doesn't make it unlawful to fire you for poor performance
I think it's worth talking to a pro about this, but it's not worth spending a lot of money pursuing it, mostly because of (a). If you were a US resident, I'd say (b) and (c) are hurdles low enough that you could plausibly shake a settlement loose, but (a) is a very high hurdle.