Their job often involves interviewing many people, and to do that and get useful results you want them unbiased (for the same reason as you want a jury that doesn't already know about the trial).
1. Having Tesla keep their mouths shut results in more unbiased people. Kicking Tesla off the investigation is in large part a deterrent, not a corrective action.
2. This change also involves giving Tesla less access to data that they might leak. Information collected from the car's logs is under NTSB control (in past cases, for example, American Airlines was punished for making its own copy of the black box before handing it over). You can reduce these issues by not sharing information with an unreliable party.
> 1. Having Tesla keep their mouths shut results in more unbiased people. Kicking Tesla off the investigation is in large part a deterrent, not a corrective action.
This purpose is in plain violation of the principles of freedom of speech, and the first amendment. The government is not permitted, morally or legally, to punish people for speaking. As such I'm not counting it.
> 2. This change also involves giving Tesla less access to data that they might leak. Information collected from the car's logs is under NTSB control (in past cases, for example, American Airlines was punished for making its own copy of the black box before handing it over). You can reduce these issues by not sharing information with an unreliable party.
This could be a legitimate purpose, but it seems so minor that short of the NTSB mentioning it I'm skeptical. The gain doesn't seem to be worth the loss of working closely with the manufacturer...
"fire in a crowded theater" is largely repealed and now requires "imminent lawless action" which certainly isn't the case here. Please read more about it here [0], written by a lawyer. Ignore the headline, the author wasn't pleased with it either [1].
Generally exceptions to free speech are extremely limited, "because we don't want you to bias people" is definitely not within an exception.
Jurors are routinely forbidden from discussing the case they are trying, parties to a settlement can be barred from discussing it, etc., etc., so there are quite a bit more limitations on "free speech" than that.
