Unless you consider it as funding in a seed round. These days, OpenAI is worth double digit billions at the very least. If Musk funded the venture as a startup, he’d have increased his net worth by at least a few billion.

it was not his intention to spend these money on funding some startup with expectation of future profit, otherwise he would invest this money into some startup instead of non-profit OpenAI, or even requested OpenAI equity. Imo(non-expert) court unlikely will buy such approach.