Update: Climber Chad Kellogg filed a report from Everest base camp today (April 30) on the incident. He posted images and his view on the fight (he was high on the mountain but not directly involved) in a post, “A Series of Unfortunate Events.”
In sum, Kellogg confirms reports that the fight began when Ueli Steck, Simone Moro, and Jonathan Griffith were climbing near fixed lines between camp II and camp III. Kellogg also details the violence, including an alleged stabbing:
“Ueli said that he was confronted by the mob and was immediately hit in the head by a fist followed by a rock to the head. Melissa [Arnot] pushed Ueli into the kitchen tent to protect him from the mob. The Sherpa men would not hit a woman so she was the buffer of protection from the very angry mob.”
Kellogg continues: The [Sherpa] men promised that if Simone came out on his knees and begged for forgiveness he would not be hurt. Simone tried to get out of the tent on his knees when he was beaten and forced back inside. A while later Melissa asked Simone to get back on his knees outside the tent and ask for forgiveness again. She had been assured by the instigators that he would not be hurt.”
“So Simone got on his knees to ask for forgiveness and was kicked under the chin, someone tried to stab him with a pen knife, but fortunately the knife hit him in the padded belt of his backpack.
Read Kellogg’s full report, “A Series of Unfortunate Events.”