A quick search of my master-list for Sussex crashes throws up nothing that ties in with this, and I cannot find a Police report either. I would expect there to be one. My work with Chris Goss and Norman Franks on 1941 losses seems to indicate the aircraft crashed in Kent, but I will delve further.
I see that he was 41. Pretty old!
There must have been a reason for his burial at Southease, and I suspect that it was either where he or his wife hailed from. Even although there is no local knowledge that ties into the Vaughan family I have often found that burials like this end up being in the spouses home town/village, in which case the maiden name of Christine Vaughan might start to lead to some clues.
Either way, I am pretty sure he did not loose his life in an aircraft related incident at or anywhere near Southease.