Please, just shoot me.
Scenario:   There is this someone with whom you've "fallen out".  Say you got pissed at them (for good reason) and then they decided meh, whatever, not worth acknowledging they treated you like shit and so pissed off-ness grew into being miffed, which grows into a mentality of 'fuck you then' and more than a month goes by and there's not a single word exchanged and for the most part, you've written this person off in large part because you come to feel they don't care if they appear to have screwed you over and it just all seems like they would rather write you off than resolve their inability to make and keep a fucking date. 

Okay.  Then.  Say one of your bosses mentions he's got a few places he's looking to get some prelim info on setting up "team building activities".  You gag, you roll your eyes, you imagine sicknesses to which you will fall prey in order to avoid such an outing but of course you agree to look up these places and give them calls to see what they offer and if you can set one up for the next week or two (and you are of course pleased your boss is such a nitwit he can't plan ahead because this already sounds ridiculously unlikely).  And you hold back openly rolling your eyes when you're asked to help and call this one place that some other exec had worked with previously.  Stupid admins on vacay.  Like that's my job?!  Whatev.   

So, you call and there's something maybe lingering in the back of your mind that is akin to a silent sort of scream but you can't tell the difference between that and the normal sound of yourself silently screaming which occurs everyday just because.  Ring ring. 

And then the person who picks up on the other end of the line is all, "Hello this is Jackass With Whom You Have Fallen Out, how may I help you?"

*instant recognition of voice begets mortified panic*

And instead of reacting with, "You could fuck off!" you instead are wise and just slam the phone down.  And then hear that that silent screaming is actually real screaming coming out of your open mouth.  So you shut your mouth and go drink some coffee and then curse the fates and your own stupidity for not matching up the name of the place you were calling with the name of the employer (one of, like, dozens!) of this person and you hit your head against the desk a few times.  How is anyone supposed to think clearly before noon?!?! 

And then your phone rings.  Your work phone from which you had just placed this Call of Doom.  And the ring is indicating an outside call.  So you pick up with trepidation and answer with a mere, "...Hello?" (no way are you going to say," Hello, this is Dumbass"--too obvious).  And then there's silence.  And you peer at the number on the caller ID and it's some cell phone from Maine but of course if you were this person who you know is calling back the number which called them, they'd grab someone else's cell to call from.  Because it's just what they would do. 
And then you finally hang up because this is just awkward but you know your mere, "hello" was enough for them to recognize your voice. (You should have faked an accent or something!)  And you know they could look up the number prefix and trace it likely to your work which they know.  And so there you are.  Sinking pit in stomach.  Doom.  Woe.  Thinking WTF.  Damn work!  Damn myself!  Stupid!  Because how does this not look like you stalked them or something?!?  Damn it! 

So.  Now.  Now you're filled with an urge to explain yourself because YOU WERE SO NOT STALKING.  That, and you've never been good at ignoring things.  Or denial.  Or anything other than saying exactly everything you think and feel.

And so the idea occurs of sending an email saying something like, "Holy shit, well, that was awkward.  Here's what happened.  How did things between us get so damn awkward?  BTW, if anyone calls back from where I work trying to set up a crapass team building thing at your work, please tell them no way so the awkward doesn't escalate.  Kthankxbi."  Or do I ignore?  Head in sand?  Denial?

HALP!  *headdesk headdesk headdesk*