So, I've asked around no one will me how to smack someone with the lancer.   I was under the impression you couldn't smack anything with the lancer. Five minutes ago I saw someone do it repeatedly and he would not answer my pleas.
Someone freakin' tell me. 

You mean over the head when you are downed?

When someone's down hit b, instead of revving your saw you'll just bonk them on the head.

I am talking about while you are standing there.  I guess this could have been a glitch.  The odd thing is that the dude killed a wretch and then smacked another guy.  Maybe I was lagging and didn't see him switch guns.

Maybe he was wielding a hammerburst, cause you can get smack happy  with one of those, all you can do with the Lancer is rev the saw or bonk someone like i said earlier.

That said, was it someone you were playing horde with? Or was it an NPC or a bot? Cause sometimes the bots can and will glitch out and do something that you cant pull off.

Look, I've played 21 hours of horde mode alone.. I say this to note that I know what I'm referencing.
This dude was smacking people with a golden lancer.  Standing there and smacking people.  No revving, just that swift elbow move. There is no way it was a hammer burst because he had a sniper rifle on his back.  It was odd.. I can only chalk it up to a glitch.

You sure it wasn't a golden "Hammerburst"?

Also, maybe I'm not understanding this, but what does having a "Longshot" rifle on his back have to do with anything?