I just saw that clip when it was linked on Twitter. When the second brawl happened so quickly I was wondering whether the video would end with an abandonment - particularly with less than 10 minutes left. I think there's a strong argument that if a referee knows it's likely that there's been serious foul play that he hasn't seen clearly enough to take action over which the players appear likely to want to take retribution for, safety suggests abandonment. The willingness to punch in that manner wasn't limited to the players who were sent off, and in those circumstances it doesn't seem safe to continue.