Yes, I get that the Shadowserver Foundation does good work. And that they acted quickly, after being pointed to your tweet.
However, if your tweet hadn't gotten traction, and if Namecheap hadn't been proactive, you'd likely have never gotten the domain back. I mean, you had the Namecheap CEO on the case! And for a business losing a domain like that, it'd probably be fatal.
I get that many think that Americans are hugely too litigious. But there is the argument that there ought to be compensation for damages.
You say that "[t]he primary loss I suffered was in terms of time". But arguably your time is worth something. Such as your customary billing rate, times three.
Edit: Or just send them an invoice. At perhaps 50% over your customary billing rate, given that it was a rush job.