halacha - Israeli Chazzan outside of Israel says "tal umotor" at the right time for him but not us

We know that the shaliach tzibbur must follow the local custom even to the extent of his own silent Amidah .

What should be done, then, when a resident of Israel who is acting as shaliach tzibbur outside of Israel between 7 Cheshvan and 4/5 December, already said “vetain tal umotor”in the repetition of the amidah?

It seems to me that he must correct the mistake; is that right?

Answer

See the article here: http://rabbikaganoff.com/archives/1777

My short summary is that most poskim hold he should not be chazzan even if he is an avel. R Shlomo Zalman Aurbach holds that he may be chazzan if necessary and should recite according to the local custom. We see everyone holds he should not change from the community.