Well interestingly this is a major issue in red light camera cases. Initially as cities were implementing red light cameras, the ticket and court case were all essentially automated.
In many jurisdictions this was challenged on multiple grounds, but one of the biggest issues (which most courts tending to agree with) is violation of the defendants rights to cross examine the State's witness and improperly introducing the video into evidence (generally it was introduced by affidavit from some record keeper in the camera company).
Its really a fundamental rights issue.
On the other hand, if the camera doesn't show everything the camera software is in effect testifying--and it comes down to if there are any flaws in the software. The government does not have a good track record on this--breathalyzers inherently are relying on the software and the manufacturers won't permit examination (discovery refused, there goes the DUI case)--so in some places it's been declared unquestionable.
(Never mind that the breathalyzer inherently has a considerable error margin due to biology--the ratio between blood alcohol and breath alcohol varies from person to person. Quick screening test, fine, evidence for conviction--not in my book.)
I would like to see the system modified somewhat--in criminal trials everyone has to disclose what they are going to present anyway. The other side should be required to indicate if and in what way they are going to challenge the evidence. If there's no dispute about where the camera is then nobody need be available to testify to where it is. (As it's cloud there's no issue of when.)