The United States National Highway Traffic Safety Administration (NHTSA) recently released a report clearing Tesla of any wrongdoing in a May 7, 2016 incident, where a driver was killed in a Model S while the vehicle was operating in Autopilot mode.

In the 12-page report, it described Tesla’s Autopilot, an advanced driver assistance system, “require the continual and full attention of the driver to monitor the traffic environment and be prepared to take action to avoid crashes,” and added “the systems have limitations and may not always detect threats or provide warnings or automatic braking early enough to avoid collisions.”

Tesla had previously stated that the Autopilot system comes with an explicit warning that drivers must be ready to take over controls if needed, a point that the safety administration fully acknowledged in its report. As a result, it “did not identify any defects in design or performance of the AEB or Autopilot systems of the subject vehicles (referring to MY2016-2016 Model S) nor any incidents in which the systems did not perform as designed.”

“A safety-related defect trend has not been identified at this time and further examination of this issue does not appear to be warranted. Accordingly, this investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that no safety-related defect exists. The agency will monitor the issue and reserves the right to take future action if warranted by the circumstances,” the NHTSA stated at the end of its report.

Responding to the NHTSA’s report, Tesla released a statement saying: “At Tesla, the safety of our customers comes first, and we appreciate the thoroughness of NHTSA’s report and its conclusion.” In the incident last year, Joshua Brown was killed when his Tesla, with Autopilot engaged, drove under a tractor trailer, colliding with the windshield of the electric vehicle. According to a police report, the vehicle’s roof “was torn off by the force of the collision.”