I'm trying to find any confirmation that they actually threw rocks or whatever at border guards. I'm seeing that they tried to move toward the San Diego border and got blocked, so they advanced toward the next border crossing over and were met by riot police, and then a few tried to scale the wall and that's when tear gas got fired. Then Mexican federales drove them back. My assumption is that the moment when they met the riot police is what's qualifying as "attacked border guards."
XI Wiki



