Q. If the Baal Tokea on Rosh Hashana keeps on making mistakes in the shofar blowing is that considered to be a siman ra'a or bad omen for the congregation?
A. Mishna (Brochos 34b) teaches that if a Shaliach Tzibur that made a mistake, it is a bad omen for the people that send him, since an agent representing someone is like him.
Teshuvos Vehanhogos (O.H. 5: 176: 6) mentions that it applies also to a Baal Tokea.
Horav Shlomo Miller's Shlit'a opinion is that siman ra'a does not necessarily apply to a Baal Tokea, that keeps on making mistakes by shofar blowing, since in essence he is not a shaliach representing the congregation.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a