Ha, I was collecting mistakes in Russian speech to post it later, but it turns out there's a topic already, and a big one.
Yeah Russian voice over is total crap. They speak with accent, I don't know, Ukranian? And they sound totally unrealistic and actually pretty stupid. And yeah, they use wrong words and pronounce some words incorrectly (not accent, just incorrect).
Also, the translation itself feels like whoever's done the localization was using Google Translate or worse.
For example,
1. When you throw a small medkit, the soldier says "here's your medical-sciences", if you translate it back into English. In Russian when we talk about taking pills we don't use the word "medicine". "Medicine" always means the science itself. But in BF4 they just say it like in English which is absurd to Russian speakers.
2. When you give a defence order, the soldier says "You have to defend that target, right after." Yeah, right after. Not right now. After **bleep**ing what?
3. "Medpack" is translated as "med bag". Again, we have the very common and specific word for it - "aptechka". First aid kit - "aptechka pervoi pomoshi", any medkit - just "aptechka". In BF4 "medical bag" sounds totally bizarre. It's like the interpreters looked at "med" and at "pack", looked them up both in dictionary, separately and went "Ah-HA! Bingo!".
4. When that Russian voice I'm beginning to sincerely hate talks about defence he uses the proper word for "defend", but puts accent on the wrong vowel and uses wrong word ending. It should be "oboronyat'", but he says "oboronit'". Just so you get the idea .. imagine in English version instead of "Defend that point" the soldier would say "Defenceness that point". How many US/EU players would freak out on that?
Jeez guys, if you can't find localization contractors of at least average quality, you can always ask the native community for help.