Just to respond to this for anyone can find benefit with this problem,
1- For me when i was downloading the game (i had near full disc space) althought i have enough space still for the update, this game patches seems to go with unpacking system, meaning they "require more space to update" (even though the update may be 10gb it unpack to 50gb in that sense) if no space were found (if you have 20gb empty space) they go regular download (high sized and almost it does download the whole game to patch it).
2- Don't Interrupt the network by pausing and changing network, the unpacking require this, if you change network or cancel this whole unpacking is messed up, game update will do normal patching as in 1.
still have questions about this in my case and not fully proved but hope this help
