Tesla CEO Elon Musk and NTSB chief Robert Sumwalt spoke this past weekend about the agency’s ongoing probe into last month’s fatal Model X accident.

In a statement to Reuters, NTSB spokesman Peter Knudson noted that the Tesla CEO and the agency’s chief discussed several points during their conversation. Among these are the NTSB’s investigative process and Tesla’s initiatives to address safety recommendations that were issued last year.

“NTSB Chairman Robert Sumwalt had what he described as a very constructive conversation with Mr. Musk over the weekend. They discussed the investigation of the March 23 Tesla crash, NTSB investigative processes, and Tesla’s work to address the safety recommendations that were issued last year.” Knudson said.

Tesla and the NTSB were recently engaged in a spat over the electric car maker’s decision to release information pertinent to the agency’s probe. A few days after the investigations began, pictures of NTSB investigators retrieving modules from the ill-fated Model X emerged. The agency later confirmed that it was able to recover the Model X’s restraint control module and its infotainment module. Tesla also released an update outlining what it knows so far about the Model X crash.

Tesla released an update on March 30, stating that Autopilot was engaged when the electric SUV collided with the highway barrier. According to Tesla, Autopilot was activated with adaptive cruise control set to minimum. The driver also had roughly 5 seconds and 150 meters of unobstructed view before the Model X collided the barrier, but no action was taken.

On April 1, the NTSB issued a statement saying that it was “unhappy” with Tesla’s release of investigative information. In a comment to the Washington Post, NTSB spokesman Chris O’Neil expressed the agency’s reservations about Tesla’s preliminary explanation.

“At this time the NTSB needs the assistance of Tesla to decode the data the vehicle recorded. In each of our investigations involving a Tesla vehicle, Tesla has been extremely cooperative on assisting with the vehicle data. However, the NTSB is unhappy with the release of investigative information by Tesla.

“We will work to determine the probable cause of the crash, and our next update of information about our investigation will likely be when we publish a preliminary report, which generally occurs within a few weeks of completion of field work,” O’Neil said.

Responding to the NTSB’s statement, Elon Musk tweeted that Tesla’s policy has always been to release critical crash data, in particular, information that affects public safety. According to Musk, doing otherwise would be “unsafe.”

“Lot of respect for NTSB, but NHTSA regulates cars, not NTSB, which is an advisory body. Tesla releases critical crash data affecting public safety immediately & always will. To do otherwise would be unsafe,” Musk said.