URGENT: Huge server side bug/issue

I have also noticed this, as well as probably related issue of chunks reloading in game, which i have experienced twice now. The latest was witnessed by both Blargh_14 and I. We had mined a long tunnel, and when returning, found that a group of chunks we had gone through had reloaded to their previous state(evidenced by the rediscovery of diamond in the same areas) I do not remember much correlation with any in game disturbance, but there was a substantial amount of lag throughout.

I didn't get the chance to tell you, I redug that tunnel, and I found out something.

only pieces of it reloaded, and it had dug out areas inbetween them

tunnel, chunk, tunnel, chunk, I only had to dig out the chunks. This happened every... 20? 30? blocks which is too small for an entire minecraft "chunk" and freaked me out thinking about this phenomenon.

Edit: same thing happened with 2 separate chests, the cobble chest unchanged, and the one with diamonds lapiz and saddles changed back. -.- my luck