A person whose lawful rights--or those of another--are endangered, commits no crime if he injures other legal values in order to avoid a greater harm, provided all the following circumstances occur:
1. the danger is clear and present or imminent.
2. the danger has not been intentionally provoked by the person in question.
3. the danger cannot be prevented otherwise.
If the person whose lawful rights are endangered is duty bound to assume the risk involved, this Article will not apply.