Hi- I just completed an SFO-LHR mile run earlier today. Original landing time was 6:55 and though we took off late from SFO due to a tire change we landed at about 7:00ish. HOWEVER, as stated above, it took a while to actually get to our gate and then there was actually someone AT our gate when we got there, so they had to be towed out. Probably off plane by 7:20 or so, then waited approx. 30-40 min. in a VERY long security line for people for flight connections within T3- then directly to above-mentioned airline desks to change my return flight to the 9:50. All this completed by around 8:20-- so an hour would not have worked today.