I've seen multiple times now that the DayZ Dev say they cannot replicate the data check fail issue. Here's how I've been able to replicate it multiple times. Please note that this does not work 100% of the time. But I have had it work several times so I've pinned it down to a pretty complex set of actions.

For some reason it only seems to work if you're moving around, what I mean by that is, it's easier to replicate this issue after covering some ground.

Once you have covered some ground, drop several things from your inventory, seems to work best if you put things from your inventory into an item such as a car. Step away from the car after dropping items into the cars inventory. Wait roughly 15 seconds and then leave the game while waiting the extra 15 second logout timer. Once you've hit the main menu, wait roughly 45 seconds to a minute, "just about long enough to go use the restroom".. <~~how I did it unwillingly the first time. Now log back into the same server. If done correctly you will get character data check failed.

I've also noticed that the 15 second spawn out timer no longer saves the gear on your character. What I mean by that is, if you pick up an item and that log out shortly after, when you come back into the server the item that you picked up before logging out will no longer be in your inventory.