When a vehicle crash occurs, that embedded system should no longer be treating data as "temporary", but as what it now is, civil and potentially criminal evidence, and it should be preserved. To go to the effort of creating that data, uploading it to a corporate server, and then having programming that explicitly deletes that data from the source (the embedded system), certainly reads as nefarious without easily verifiable evidence to the contrary. The actions of a company that has acted this way in no fashion lends any credibility to being treated as anything other than a hostile party in court. Any investigators in the future involving a company with such a history need to act swiftly and with the immediate and heavy hand of the court behind them if they expect any degree of success.