Why is it uncertain who fired the first shots during the ATF raid?

The uncertainty regarding who fired the first shots during the February 28, 1993, ATF raid on the Branch Davidian compound near Waco, Texas, stems from the chaotic nature of the initial confrontation.

While federal agents launched the raid to execute search and arrest warrants based on allegations of illegal weapons stockpiling, the Branch Davidians had been tipped off in advance and were prepared for the arrival of law enforcement. As more than 70 agents approached the complex, gunfire erupted immediately, leading to a two-hour battle that resulted in the deaths of four federal agents and six members of the religious group. Because the event devolved into a sudden, intense shoot-out, investigators and historical accounts have been unable to definitively establish which side initiated the exchange of fire.12