Principle of Doing Good
Principle of Doing Good (Arabic: قاعدة الإحسان) states that, if a person accidentally does damage to another person's property while they were attempting to assist that person, then the person who did the damage does not bear any responsibility to the damaged party.
For example, if somebody sees that another person's house is on fire, and attempts to put out the flames, but in the course of doing so does damage to the property (like water damage from fire hoses), the person who put out the fire is not responsible for the damage that they do. This is true even if the person is not succesful in what they were trying to accomplish. Evidence for this is in the following verse:
لَيْسَ عَلَى الضُّعَفَاءِ وَلَا عَلَى الْمَرْضَىٰ وَلَا عَلَى الَّذِينَ لَا يَجِدُونَ مَا يُنْفِقُونَ حَرَجٌ إِذَا نَصَحُوا لِلَّهِ وَرَسُولِهِ ۚ مَا عَلَى الْمُحْسِنِينَ مِنْ سَبِيلٍ ۚ وَاللَّهُ غَفُورٌ رَحِيمٌ
[9:91] It shall be no crime in the weak, nor in the sick, nor in those who do not find what they should spend (to stay behind), so long as they are sincere to Allah and His Messenger; there is no way (to blame) against the doers of good; and Allah is Forgiving, Merciful;