Your post raises two issues: What was the primary rifle in France? Based on what I have seen and read, only the Marines carried the 03 into Europe, the US Army carried the M1917. I am aware, from American Rifleman articles, that Regular Army Units were relieved of their 03's and given M1917's before shipping across. This was how 03 serial number one was found, the Private who had the rifle did not want to give it up, he created enough of a fuss that his unique rifle was identified to authority. I would like someone to give number of the actual 03’s that were in Europe.
And I believe this why not a word of the defective single heat treat rifles appears in print, or in a whisper, during WW1 or years after. If an adult had been in charge of the War Department and found that all of those one million 03’s made to date were suspect, the correct decision would have been to stop wasting money, stop production, and use M1917’s. There were over two million M1917’s made, more than enough to arm the AEF, the rifle was 100% successful as a combat rifle, and it was a more advanced combat rifle than the 03. However, the M1917 was made outside the Government Arsenal system. The Army wanted to keep their Arsenal lines going and they liked the 03.
The second question is how did Hatcher get these safety reports? Safety incident reports are not released to the public or to anyone in the Army. Only Safety investigators and law enforcement have access. That is why you cannot find anything about Army accidents, incidents, etc, in the public domain. The only reports you will find are those that are so scandalous that they make the evening news. Following your logic, since there are zero reports, there are no accidents, now, or then. To pry anything out, you need to get a lawyer and work a FOIA. Good luck on finding an accident report database from 1917.