If there has been active pushing for an hour and no head on view then yes, it is common for the doctors to come in and see what is happening. Depending on condition of baby then they will either let you keep going or suggest an intervention. As you said OP bubs head was at a funny angle, I would say that bubs head was acynclitic - so rather than coming straight down was slightly sideways. Sometimes this can be corrected during a vacuum, but not always. They should have offered you a debrief the following day to answer any questions and ensure you understood exactly what happened and why the decisions that were made were made.