Elon Musk is a US interest. The US is a bunch of business interests in a trench coat, and they don't always agree on everything. Some want to do business with China, some want the Chinese competition destroyed, and some want to create tension so they can sell more weapons.

The idea that Musk is "counter" to US interests is wrong, he just represents a faction of the ruling class that's not on board with the (trade) war on China. Since it's not in the interest of the working class to have a US-China (trade) war, neither in the US nor anywhere really, he is inadvertently aligned with the interests of the majority of humanity on this one.