Context now that the editorialised title has changed, this is a core Bitcoin developer. These things happen every day, but happening to a core developer (if confirmed!) who has a deep understanding of the systems and security indicates just how fragile crypto can be (in my opinion)
Based on the other comments in this thread it looks like he didn't bother using a hardware wallet (which is literally something that's recommended on bitcoin.org[1]), and kept his wallet.dat on a server exposed to the internet. You're trying to paint a story of "well if a bitcoin core developer can't secure his coins, then who can!?!?", but in this case it looks like he was being an idiot. You can lead a horse to water, but you can't make him drink.
[1] https://bitcoin.org/en/choose-your-wallet
edit: on twitter he denied that he kept his wallet file on a server