This happened to me earlier in a wager match.  It was too funny and annoying not to share.  Enjoyst! 
 
http://www.youtube.com/watch?v=dqecsc_JjV4

There is a theater mode thread here. Toss it there for more to see

That's kind of funny, but I would be pissed if that happened to me in a wager match

Yeah thats complete bullshit. I would also be pissed.

Wow. I would have gone bananas and raged quit.

I hate it when people knife me at medium range while I hip-fire at them.

Cool knifing bro^^

Will someone get that man a medic over there?!?

To be honest, knifing as a whole is bullshit in Black Ops. It does need fixing!

That video reminds me of that knife hack in battlefield 2 were you could knife people 40 feet away, haha, those were dark days.

sometimes game engines do fucked up shit.
 
You weren't playing the 10000 points matches were you? That would suck!

Was he the host? Did he have more green bars?
 
/PC player who remembers MW2
 
 
edit: Here's something I wrote elsewhere earlier today about Blops netcode :
" Like I cry out all the time, online FPS netcode has gotten worse over the years. If I died in QuakeWorld it was because I made a mistake or I got owned, and I started that shit on 56k. Today on 100mbit fiberoptic, I die for the same reasons in that game.

In Blops most deaths I die happen because it's like my enemies are Nicolas Cage out of Next."

That is uncool but I miss so many knifes I think should hit that reducing the hit detection would only make me more angry.

This is probably a latency issue.

Lag mothafucka.

Wait, what does he need over there?

WHERE IS THE FUCKING MEDIC?

This is new and exciting...
 
Since this shit never happened in any other CoD's or shooters like it before eh? 

the knife is the worst thing COD made popular.  it's so stupid and hit detection is terrible.  slash the air infront of someone and they die.  It also breaks up close fights in a retarded way... so I'm gunning someone in the face, and they press the knife button so they get the kill.  how about a quake 3 gauntlet melee where it's just a humiliation weapon, and not a cheap sprint through gunfire free kill weapon.  

The hit box for knives in every COD game is fucking ridiculous. You should play a good FPS, where the focus is actually shooting people with bullets.

I just came off of MW2 before going into BlOps, and I gotta say that it isn't just the same old bull shit. 
 
It is fucked up. 
 
I have encountered situations, several times in fact, where i have been able to knife someone or have been knifed from almost halfway across a room. I've also seen several Kill Cams where slashing the air next to a player, even if they were almost completely behind the attacker, results in a kill. 
 
Now honestly, I don't have a problem with the knife. I think Halo actually handles the concept of melee kills a bit better, but in any event I have never had a problem with them in a Call of Duty game until BlOps. The hit detection is so off that it makes close range weapons like shotguns and some of the SMGs almost completely useless under the circumstances in which they should normally excel. There have just been too many times where I know I should have died because my opponent had fired about twenty rounds directly into my chest, yet somehow I get a knife off and down him before it finishes me off. 
 
It's a complete crapshoot too, it's like the melee system is making a fucking dice roll every time a knife goes off.

Caught your Achilles heel brah

" In Blops most deaths I die happen because it's like my enemies are Nicolas Cage out of Next."

If he needs a medic he should play TF2, and even if he doesn't he should still play TF2.

medic standing by
 
it sucks for that person.

He swang that knife so hard and fast the resulting breeze killed you.

Maybe it's just me, but who gives a shit?