I've had that issue every once in awhile long before today's mini-patch.
I usually blame it on someone on the shard duping, but I have no actual evidence for that....I've just known similar things to happen when someone is duping or hacking. Certain cheats somehow cause lag.
On LS it used to be that if you started lagging at a champ spawn, one of two guilds was about to show up. The prediction was accurate well-near 100% of the time, and the times it wasn't accurate the lag turned out to only be region-specific.
And I remember long ago entire shards used to vanish periodically, allegedly due to a single guild duping items.
-Galen's player