As has been widely covered recently, Musk said something like moats are lame, Buffett responded he's wrong and Musk said he will start a candy company. Pretty dramatic escalation. Some people said it reflects Musk being burnt out from Tesla problems, others that he both are arrogant billionairws.

After some digging, turns out Buffett is investor in BYD (Chinese EV co). Also, when Solar City came to Nevada, upsetting the Nevada Utility (owner: Buffett), the utility whined to the gov that Solar panel owners should contribute to the cost of the infra, breaking Solar City business model [1]. Solar panel owners ended up paying more than pre-solar energy times.

HyperChange derived from the 10Ks that 48% of BRK revenues is at risk from Tesla [2] Take it for what it's worth

[1] https://youtu.be/YGGk90YljhQ

[2] https://youtu.be/cCWS4XUp6Uo