I think it's plausible that grant recipients in countries other than the United States could be subject to clawback action under the laws of those countries, and the applicable limitation period may well be longer.

In my case, I won't be totally certain until the six year limitation period under New Zealand law has run. Luckily there are much more favourable defences under New Zealand law, and even if their prospects of success were higher I somewhat doubt that Sullivan & Cromwell would bother instructing New Zealand counsel to chase up a relatively meagre grant.

If your grant was small (e.g. salary/expenses for one person), you might adopt the same "she'll be right" attitude I'm taking to this. But if you're based in a country other than the United States and got a big grant then you may want to keep this risk in the back of your mind and/or speak with a lawyer in that country.

Epistemic status: I suspect it's more of a hypothetical risk than a real one, but mentioning it for completeness and for the benefit of folks with a very low appetite for risk.

Personally since my grant was probably too small to justify the effort of a clawback, and the statute of limitations had passed, I donated all of it, divided between the GiveWell top charities fund and GiveDirectly.