I sent my submission at 11:59pm GMT. The rules show the contest ending at 23:59pm GMT; there is no specificity around whether the time has to be submitted or actually in your inbox by then. With any level of respect for your fellow competitors, you would accept anything that had a timestamp of 12:00am GMT or earlier, knowing that a delay of a few or many seconds could occur while transmitting the message. Instead, you choose to interpret the rule to the detriment of one of your fellow racers, and completely nullify everything they put into the competition, based on your (negatively) chosen way of spinning the rules.
To reiterate- the rule has no clarity around whether the submission has to be sent or received at 11:59. You had a choice to make, and either would be as valid the other, so why choose the one that effectively characterizes a fellow racer as worthless, completely nullifying every moment of their lives that was dedicated to the event? To top it off, you're in the competition and you have first-hand knowledge of what it is like to compete; and you have an internet connection, and first-hand knowledge of the fact that data typically takes a few seconds to transmit.