A dog shall not be declared as dangerous or potentially dangerous if it bites, attacks or menaces a person, domestic pet or animal if:
1. It is defending its owner, caretaker or another person from an attack by a person or animal;
2. It is protecting itself, its young or another animal;
3. It is defending itself against any person or animal that has tormented, assaulted or abused it;
4. It is defending its owner's or caretaker's property against trespass;
5. The dog is a police dog, as defined in section 55.02(20), or used by a law enforcement or military official for legitimate law enforcement or military purposes;
6. If the threat, injury or damage was sustained by a person who, at the time, was committing a willful trespass or other tort upon the premises occupied by the owner or keeper of the dog, or was teasing, tormenting, abusing, or assaulting the dog or has, in the past, been observed or reported to have teased, tormented, abused or assaulted the dog or was committing or attempting to commit a crime.