So at present I have all my fields set to required. When the timer is hit you process the save function which should then redirect them, but what you are doing is also validating the required fields and as such it means the form does not submit, I can then finish it and submit it.... Regardless of time.

First you should be double validating on save, i.e. that timer hasn't been reached say +5seconds for latency. 

second, you should be skipping validation once timer has finished?