meh, dont over think it.
just play, when you get your call, d/c if u have to, take ur call, and then come back.
someone gives u a hard time, just point to this thread saying "i work and d/c intermittently"..
again, i highly doubt u'd be getting these work calls more than once or twice every (say) 6 hours?
just try to lay low with it, judge urself by how many times you pulled that shit per day, if people bitch about "yo, he rejoined" explain ur shit, if they still bitch, just sit out the map and prove them wrong that u didnt rejoin to win THAT map, its only like 10 mins, you could do smthn more productive lol.. its not a big issue.
enjoy the servers, and thx for asking ,its always better to take a risk and ask than to bottle up and get fucked later
if u're honest about ur work shit, u should be fine, again, we can always tell in time what happens (we have logs of every join/rejoin/disconnect/score/demo/gameplay/kills/deaths/etc... u could ever think of , to watch over
how hilarious would it be if you claimed you had a work call at 3 am and 3 pm on the same day (logs)... then we'd have an interesting conversation -.- lol