BNSF was purchased in February 2010, amidst the depths of the 2008/2009 financial crisis. Back then, many (including myself) thought the market would take a deeper dive.

It's true it was a big purchase, and the same general era, but I wouldn't call it the depths of the crisis.
The average S&P 500 firm was up 75% from the March 2009 lows on the day the acquisition was announced. The storm clouds were long gone by then.

I have long known that Berkshire didn't sit on their hands, they deployed a LOT of capital through the crisis period (about $46bn plus the later cost of warrant exercises). But I hadn't really thought before about the nature of the commitments being mostly of finite duration. I guess the thinking at the time was that by the time the fixed income and warrants and so on had matured there would likely be some other new big capital deployment opportunity for the funds being freed up, but this is the assumption that turned out to be wrong in a meaningful way. At that scale, there still hasn't been a target rich shopping environment except for a too-short-to-act window at the pandemic lows. (not too short for us mere mortals, but too short for people trying to deploy $100bn). The credit crunch era investments were big and made a lot of money, so we can't fault that. But it was a missed opportunity to do more lasting investments. As a random example, Costco was trading under $50 for roughly 8-9 months.

Jim