I believe it is your connection, but I will look into this further. My reasoning behind my belief is that the server is vps hosted, so there shouldn't be any lag at all, unless the vps is getting ddosed, which is very highly unlikely as the server is ddos protected and there really is no one to ddos the server. Something that may have lead to the disconnection however are the following: Where you downloading anything? Streaming any media(Music, Videos)(iTunes doesn't count if you were). Was someone else on another computer in another room?
Somethings that could have gone wrong on my part:
Something Could have happened with your summoning?
I can see you have a familiar spawned, so did you try to dismiss it while in combat ?
If that so, that is an in-game bug that I should fix immediatly lol.
Anyways sorry about the lost items, hope there are no hard feelings, did this before or after your last donation?