Q. How come once I was at a dinner at a synagogue on Shabbat and a small fire started accidentally on the table and instead of the safe thing of putting it out, the rabbi made a poor waitress take it out on a plate (as it was burning on the plate) Is this right, to endanger the life of others? What if she tripped?

A. Horav Shlomo Miller Shlit”a pointed out, that in generations past everyone would be carrying for illumination purposes sizable candle-holders and torches (during weekdays.) We may still do it today on Yom Tov, when we move the candles from the Suka etc. There is no great concern of tripping or endangering others when done carefully. Then again, it depends on the actual case.
Presumably, the rabbi decided that there was no need to extinguish the fire which is prohibited, when other viable options exist, such as just asking the Gentile waitress to remove immediately the small fire now contained in the plate.
 Instructing the waitress to take out the plate may be considered a “Shevus Deshvus” or incurring into two interdependent rabbinical prohibitions. One is asking the Gentile to do a prohibited task, and moving the plate with the fire on it, which could be muktzah, if the candle or other burning object already were on the plate from sunset. This is permitted in need or for the sake of a mitzvah. (Shulchan Aruch O.H. 307: 5, 328: 10 et al.)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a