Perhaps interesting: the LD50 of water is roughly 6 L at a bodyweight of 75 kg.
Death by water intoxication sounds pretty difficult, to be honest. I bet that guy drank more than enough to kill himself (up to 9.5 L in 90 minutes), even without knowing his body weight.
About 1.6 L of water, but it depends on how you prepare it. Slightly higher for me in the Takeya pitcher, but I haven't weighed it (recently enough to remember anyway).
I can confirm that image is super disgusting if you haven't eaten meat in years (well, to me anyway).