Helper Field, Display Data based on "null" or "blank" in other field..

Have been racking my small brain on how to create this Helper Field.

This is a SHEET that is pulling data from our daily log. I am not sure if I can create the formula here or if I have to go to the LOG SHEET. Right now its counting all dispatched "10-50" which I still want, but if we get a false "10-50", in ROW [NEG-IRF] we put the reason. So I also need a new Field that will represent [Actual 10-50] which would essentially be a [Event]="10-50" as long as [NEG-IRF] is BLANK.

I'm pretty sure I can add the new [Column] that will count [actual 10-50]