I have drafted a nice letter to SMI/J and will send it tomorrow. I don't want to go on social media or with a travel writer about it as I am worried there will be backlash from United. I will also report it on dot.gov, thanks for the link.
I write this as I have been waiting 40 minutes on the ground in DEN for a gate, as they have more ER4s here than gates to accommodate them, yet .bomb shows an on time arrival. Lovely.