Doesn't it seem out of place that NormalChunkGenerator::recreateStructures is taking up a lot of time under a PacketPlayInFlying$PacketPlayInPositionLook method in particular?

Timings taken for 60 seconds during several lag spikes:
http://i.imgur.com/c9nJRmZ.png

My guess is the packet plays animations of player shifting direction when flying. It is understandable that new chunks would load and generate when a player shifts their looking direction, but why is there no huge load of generation when a player is on the ground? Is it because the speed of flying is higher? It's hard to imagine a player would get a lot of air time in previously unexplored chunks because ideally they would need to build a very tall structure to jump off first, then fly into unexplored territory. Still, is it a possible cause of lag?