I have it all the time (with AA) where I sit or arrive near the gate (I usually arrive at T-20) and let everyone who is queued up board before I do. I'm generally in the first row so I don't like to block people as I'm putting my bags in the overhead and boarding last prevents people from having to wait for me to put my carry on and backpack on the overhead to get past me. 85% of the time at T-20 I can clearly see the jet bridge is packed with people and I have the GA chastising me that if I don't get on the flight they are going to shut the door and leave without me. Am I pacing around the gate? No, but a lot of the times I have to rearrange my bag or I am working on the laptop and prefer to sit as close to the gate as possible to get every ounce of work done before having to board the flight. If I see an empty jet bridge then of course I board but the whole cattle call threats by the GA are to just be ignored. Many times when they scan the BP and realize I'm a EXP their attitudes change "Oh your an EXP why didn't you say so" (which is a real shame everyone should be treated equally)

Just last week I had it where I was being told that they were going to leave without me (as they didn't want to print my BP) to which I replied, but the pilot just left to get food (which he did) so how is that possible? It was another 15 minute before the pilot returned with his food order. and we pushed right at T-0.