Without that, they would have $500M less cash on hand. They shipped half of their cars in the final 10 days of Q1. Finances must have been pretty tight at the start of March. That was around the time they announced they are closing all stores, firing sales personnel, and in general tightening the belt significantly. They also had the Model Y reveal in the middle of March, presumably to raise capital via deposits. Cutting prices multiple times towards the end of March must have helped to move a lot of metal, at the expense of gross margin.
Speaking of the Model Y, I also found it suspicious that on the conference call Elon Musk wouldn't divulge the number of deposits. When the Model 3 deposits were skyrocketing he talked about the reservation count frequently. I can only suspect that the number of Model Y deposits isn't so impressive.