It's true. It still happens on 1.8, but it doesn't happen on Pe
This bug also appears in pre-1.8 multiplayer world.
Even Iron Golems can't swim! That's obvious since iron is denser than water. They don't drown though. But they would be killed by bunch of creepers, skeletons and zombies if they go on land, so going under water is a better idea than going on land.
That is 14w30b when baby doggy Greg drowned because of the bug!!!!
Poor doggy Greg...
It doesn't update even after they've been to the End. But it fixes also itself after reloging.
But it looks like it doesn't happen in LAN world
It happens to me too.
Also in 14w04b.
Try having screenshots and let us see.