Guild bank and Guild Info Log Cleared

Logged in yesterday and found out that someone stole items from guild bank and stole stuff from couple of tabs. What got attention of everyone is how log got cleared? As no GM of the guild has that option and neither does any of officers ofc. And yes, some officers left the guild that day and the day before but we can not blame anyone since the log is cleared and all the officers had access to the guild bank.

So here are the printscreens where you can see how log is erased, and see that last log is shown after getting the log of tabs cleared. (Shown time is 2PM ST on 7th August)
http://imgur.com/a/ATqvZ
http://imgur.com/a/kTodD

You can check and these next 2, about epic tab2 - There is deposit of one ring by Anncy but in log there is no withdraw. So for this tab, the Log is not fully erased, only for that item that is taken.
http://imgur.com/a/PRTJ0
http://imgur.com/a/eaQuc

And this is what was left of guild info log. Yes, it sometimes bugs but you can not see anything. How is possible to see only 4-5 last activities?
http://imgur.com/a/8oOrJ

The first one on this log is Adsadsera for which none of us ever heard of, so we have no idea who invited him and what lvl he is, since can not find on armory (probably lvl1). So our bet is on this guy, only we have no clue who he is. Was he invited, what lvl is he and who promoted him to officer rank or was it name change that does not show on armory.

If someone has experience with this, issued it before or know how this can be done or fixed, let us know. Thanks

I can confirm this. I am in same guild and i dont understand how can someone wipe the log. Yes it could be a bug but i doubt it because you can see activities that happened after it was "deleted". So i am confused, what could possibly happen? Is it possible to delete logs and how?