It is, and it also makes all of their claims of not wanting to kill civilians drop in water. If the goal was to attack army base, then when they saw the festival they should have just moved around it, instead they decided to start shooting. At that point claims of not wanting to kill civilians just doesn't make sense anymore. It also shows they just wanted to kill without discrimination. They didn't care who gets killed as long as life was taken.
I mean given that one of the goals of the operation was to take hostages it makes sense they wouldn't just leave it be. Not making any statements about their conduct during the operation, but it's a little too early to assume they just went in blasting. We already know that there are civilians who were killed by IDF fire.