Nostr has showed us how important privacy, anonymity and sucurity are, they are not nogociables in future web platforms, the next generations of payment systems need to integrate these as a core values or it will never succeeded.
This really looks like an attack on his whole phone (Pegasus-like attack) or an Apple backdoor (assuming he uses iphone) they are known to cooperate with three-letters ag**cies) not a signal issue per se.
Notes by Mostr | export