Time: Septermber 29, 2016 around 1:15PM AEST
Frequency: Only once (could not attempt reproduction)
World name: Excalibur
Character name: S'zendaril Tia
Class/level: Weaver/40
Party or solo: Solo
Race: Mi'qote male
In-game time: not noted
Area and coordinates: Limsa Lominsa Lower Decks Hawker's Alley (coordinates not noted)
Steps:
I placed the blacksmith recipe Plumed Mythril Pickaxe on my hotbar.
I opened the crafting menu, selected Linen Yarn, and clicked Synthesize. The crafting menu disappeared.
Before the crafting progress window appeared and my character knelt into the crafting pose, I clicked on the Plumed Mythril Pickaxe recipe on my hotbar. This brought up the crafting menu.
After the progress window had appeared, I pressed N to dismiss the crafting menu. This caused my character to stand up without failing the craft, dismissing the progress window, or returning any materials.
I was not able to resume crafting, begin a new craft, dismiss the progress window, or open the pause menu. The effect persisted through changing zones and NPC interactions until I exited the game.

Connection Specs
Provider: Telstra
Type: ADSL
Speed: ~512kbps