LOL.
I had to read this one until the end.
Anyone else think that the OP arrived way to late to the airport, were told they needed to pay for excess baggage, had a hissy fit, spent the next 20 minutes or so mucking around with luggage and holding everyone up, then decided to have a go at check in staff and in the meantime the flight closed?
I must admit, while check in staff are not always bundles of smiles and joy (we all acknowledge they have a very trying job at times) I have witnessed far more altercations in airports caused by the attitude of the pax than the attitude of the staff. So in this situation, especially given the 'selective' style in which the story is told, I think it is much more likely it was the pax that was aggressive, at least in the first instance.