When I have a younger group, our free play time is very limited. It's a pain because it means I have to remember to put kids "up" whenever I can't be right with them. But this past year when all my kids have been 3 and under, we haven't really had any physical issues (knocks on wood
) I keep special table toys that I can rotate in and out just for this.
Honestly at this point (third time) I'd be less concerned about laying blame and more on top of getting a solid plan together on my end to end it.