Depends.
GET IT?!?!?! *slaps knee*
No, but in all seriousness, I have had this exact situation happen to me in a RANKED game. Fortunately I was playing with a premade team of 5, so I got on Ventrilo and I said "Guys, I'm REALLY REALLY sorry about this, but you will have to cover for me for about 7 to 12 minutes. This is a Code Brown emergency!" They were totally cool with it and cracking up and making fun of me, which made them far less upset at me when I got back and enemy team had baron buff and taken out 2 base turrets lol...
Mother Nature is like a Summoner. I have to do her bidding. Let's just say that at that point she had already destroyed my inhibitor... 