Here's the jist of the answer he got;
I can't be sure.. all the handout says is "on or before Wednesday 25th", but it then goes on to say that "late submissions will be penalised as per the Course Handbook", which suggests the deadline must be what the course handbook defines it as, ie. 4pm on the given date. But you could probably argue that it was unclear.
Hmm. Can you tell I've been reading effing law stuff for the last few days..?