Citing Q1 raises red flags. A lot of things happen only at the beginning of the year, so it's not representative of the rest of the year. (Similarly, citing Q4 alone would also raise my eyebrows).
Results from all four quarters of last year are available. He could have used the annual result to bolster his argument - except of course the annual results debunk his argument.
I'm not sure what "half a billion" refers to, but here are the annual numbers[1], which are easily accessible on their investor relations page[2] or from the SEC EDGAR system if you prefer.
Regulatory credits: $1.465 B
Total revenues: $53.823 B
GAAP profits: $5.519B
To claim that the company would be unprofitable without the credits is nonsense.
Every company does financial planning. Tesla knows they sell more regulatory credits in Q1, so they can also plan to spend more during that quarter.
Results from all four quarters of last year are available. He could have used the annual result to bolster his argument - except of course the annual results debunk his argument.