https://archive.ph/JwOiE Somewhat paywall free link.
An inspection of the aircraft’s wreckage found that about one-third of the fluid in the hydraulic systems in both the nose and right main landing gears was water, when there should have been none.
WTAF? 1/3 of the fluid being displaced by water isn't some weird condensation issue; it got pumped in like that. 100M aircraft and we're using hydraulic fluid from some random ebay liquidator.