If you're talking PVP, it's not immune to lag... I often get affected by... what those of us old guys from the early-ish days of Team Fortress 2 might call a face stab. That is, getting back stabbed from the front due to lag or glitches or other silliness. Otherwise, I can only think of maybe one or two enemies with clubs which might have slightly off hit boxes on their weapons, but if you're only at the Taurus demon boss, you shouldn't have encountered them yet and they're not all that hard to deal with if you just learn to leave a little more extra room than you might seem to need.
Also a boss or two do have area/ranged attacks that are triggered with a swing of a melee weapon, but it's pretty obvious what's happening when it's happening.
As for being attacked early on by people with awesome equipment, there are bugs that allow you to do that on your own... but if you can get a friend to help (not all that easy with the summoning mechanics) then you can trade items between characters, potentially giving a low level character very nice weapons.
Sometimes you also just get unlucky and have to fight someone 15 levels higher than you.