The Talmud (Berachot 54b) teaches us that four people must say the HaGomel blessing, i.e., those who travel through the desert, those who travels overseas, those who are released from prison, and those who were sick and feel better. Sometime, on Shabbat, there are many people who need to say HaGomel. Can one person say HaGomel for the other people in the congregation? Does each person need to make his own blessing? R. Ovadia Yosef, in Hilchot Tu Bishvat (Hazon Ovadia, Hilchot TuBishvat page 354) cites the Hatam Sofer (OH 51) who explains that the Birkat HaGomel does not follow the Korban Todah, i.e. the thanksgiving korban. Had it been modeled after the Korban Todah, each and every person would have to say the blessing. However, since it is not based upon the Korban Todah, one person may say the blessing for the entire congregation, even if they have different reasons from say the HaGomel blessing. Summary: One person, who is himself obligated to say the Birkat HaGomel, may say it for the entire congregation, regardless of their reasons for saying the blessing.