I've been looking at Rash"i's explanations of Tamar's refusal to embarrass Yehuda after she was found to be pregnant and was sentence to burning. Rash"i says that from her actions, we learn that one should jump into a fiery oven rather than embarrass someone.
First of all, it was tough for me to determine where this statement comes from, but I assume it's mentioned in some Gemarra? Regardless, isn't preserving ones own life paramount (except in 3 areas where one should die, like idolatry, etc.)? One can override any commandment to preserve one's life. Tamar was possibly falsely accused of being a harlot (my question on whether her being pregnant by her father-in-law is considered harlotry or zonah). Even if not, refer to Rash"i and Siftei Chachamim that question if she should have been sentenced to burning as she was neither engaged nor married.
In short, I don't see how Tamar's actions is an example of that principle. Shouldn't Tamar have challenged a false accusation and protected her own life? And, practically, is one actually supposed to jump in a fire to avoid embarrassing someone?