Sounds like it was running backwards. I have seen a John Deere 730
2 cylinder diesel run backwards. It was running on a dyno when it was lugged down and died. When he restarted it, it ran backwards. He was trying hard to kill it and did get it done. They don't last long with the oil pump running backwards. If you have a clear precleaner and oil bath breather it is real evident as you will fill the precleaner with oil. I was also on a Case 930 diesel and I was being pulled started and it fired backwards. It filled the precleaner with oil as well. It took a split second to to figure out what was going on. First time I had experienced it. Detriots seem to do it more often than any other engine. Being a 2 cycle diesel I would think contributes to that.