Yes but they did so with the understanding that they had the ability to pull the plug with AZ-5. The designers and/or the overall operating authority knew that you needed to use AZ-5 earlier because of the initial reactivity of those graphite tips, but plant operators had not been informed.
RexStardust t1_jc27u7l wrote
Reply to comment by BrightCharlie in Why were the control rods in the reactor featured in the HBO series 'Chernobyl' (2019) tipped with graphite? by Figorama
Yes but they did so with the understanding that they had the ability to pull the plug with AZ-5. The designers and/or the overall operating authority knew that you needed to use AZ-5 earlier because of the initial reactivity of those graphite tips, but plant operators had not been informed.