See Yabi'a Omer vol 5 siman 15: since in Eretz Yisrael they have already been saying tein tal u'matar from 7 Cheshvan, if you make a mistake in chu"l and add it in when you weren't supposed to you don't have to go back and repeat.
(I would not have figured this out from reading O.C. 117:3.)
"you don't have to go back and repeat"
ReplyDeletekal v'chomer? if Hashem will go so far as to send bodies by underground channel to Yisra'el for techiyas ha'meisim, then those >living< abroad who mistakenly place themselves here by an annual, routine channel of words, are immediately acceptable in His sight? or is the G-d jealous of any unauthorized 'travel' to the Land? or is the kal v'chomer simply off: 'arrival' here [identification] must be anything but routine or accidental?