Any dog bite incident is always the responsibility of the owner.
After all an owner should have sufficient knowledge of their dog's character and temperament to ensure it is under control at all times. If the dog is nervous the owner should advise people not to approach or make sudden movements towards the dog as it might bite out of fear. If the dog is dominant then the owner should advise people not to make direct eye contact when approaching and the owner should ensure a proper introduction. If the dog is aggressive or has high drive then it should be muzzled in public places, or at a minimum on a leash, to ensure the safety of toddlers, small dogs, squirrels, etc.
Above all a dog should be well trained and fully submissive to its master.
That being said even the best handlers with the most capable dogs have experienced an instance where a dog has behaved in an unexpected manner with varying consequences, and for this reason it is important that you are aware BOTH of your body language when approaching a dog (as per mails above more or less) but MORE IMPORTANTLY you should be aware of a dog's body language towards you when it is approached as they often exhibit specific signs prior to biting. I will not go into a dominant dog's body language prior to a bite because those signs are pretty clear and by the sounds of your experience it was not a dominant dog that bit you but rather a fear biter (dominant dogs do not easily let go once a bite is established, or they shake the head as a result of their prey drive and this usually results in more damage than you experienced).
Here are some key warning signs for you to watch out for that should inform you not to approach a dog without care and especially not to try to pet the dog near its head (as most of us do) are as follow:
1. Head Low
2. Mouth Closed
3. Intense expression or staring at a specific point
4. Yawning
5. Dog licking its on nose
6. Standing frozen whilst having one front paw raised (unless they are pointers)
7. Head tucked in towards chest and looking up at you
8. Raised hocks
9. Raised tail
10. Lip curling
These signs are not a guarantee that the dog is not trustworthy but if more than a few of these signs are exhibited then it is a pretty clear indication the dog does not particularly want to be approached at that moment irrespective of what the owner might be saying so in those instances approach with care.
Finally dogs are truly man’s best friend and given the amount of dogs out there the likelihood of being bitten is miniscule so try not to let it affect your behaviour towards other dogs in future as the key to being safe around dogs is knowledge about them and not be nervous or fearful of them.
Hope that helps.
Best,
NC