this isn't isolated as i've read a similar report from russia;

https://dailytimewaster.blogspot.com/2024/08/in-1958-record-grizzly-for-that-year.html

I, on the other hand, have shot several squirrels with my Sears Single Shot .22.  They were not records, but they were tasty. 

On 10 May, 1953, Bella Twin was hunting small game with her partner, Dave Auger, along an oil exploration cutline south of Slave Lake, in Alberta, Canada. She was 63 years old.

They saw a large grizzly bear coming toward them. Wishing to avoid an encounter, they hid off the side of the cut.

But the bear kept coming closer and closer.  The bear got so close that Bella Twin thought it less risky to shoot the bear than to not shoot it.  It was probably only a few yards away. Some accounts say 30 feet. Perhaps she saw it stop and start to sniff, as if it had caught their scent. We may never know.

She shot at the side of the bears head.  Knowing animal anatomy very well (she was an experienced trapper, and had skinned hundreds, perhaps thousands of animals) she knew exactly where to aim to penetrate the skull at its weakest point.

She shot, the bear dropped. It was huge. She went to the bear and fired the rest of the .22 long cartridges that she had, loading the single shot rifle repeatedly, to “pay the insurance” as Peter Hathaway Capstick said.  She made sure the bear was dead, and not just stunned.