Consider whether the chicken itself was the problem. In my experience, sometimes those picnic fails come from the sides that sat out too long, not the main dish. Could've been the heat, the mayo-based coleslaw, or just a general bad day with kids.
Seems a bit dramatic to say the chicken ruined everything. I mean, @emmas19 has a point about small things, but idk, maybe the kids were already tired or hungry before the picnic. Picnics can be messy, and fast food chicken isn't exactly fancy eating. Could've just been a bad day, not the bucket's fault.