This could serve as a cautionary tale. A good reason to diversify holdings between banks and other stores of value like bitcoin.

Yeah, not only bitcoin but I would say some stocks paying good dividends as well. Income is very important to pensioners, and one would think that they wouldn't keep the entirety of their savings as cash. Stocks and bitcoin would not need to be held by a bank, of course, so the risk of someone stealing all of it would be lower, presumably.
Banks have pulled stunts like this for years.
Not sure I agree with that entirely. This seems like an aberration to me, a rogue banker not following the bank's policy. It wasn't the fault of any bank but rather a thief bent on scamming people.
In the states, the money would be insured against this kind of scam (by the FDIC), and I don't recall the last time I read about something like this guy in the U.S.
It is scary that this could happen. Unfortunately the elderly are often targets of scammers, and I'm not exactly sure why. One would think that after a long life they would be wary of those who would perpetrate scams, but they seem to fall for many of them. Sad.