Great lighting is the start to a great photo
As an animal, action photographer, we are never guaranteed great lighting! Outdoors, set up of equipment, direction of the sun, never using a flash, all these things can make or break an image. We do not always get the ability to set up where the lighting is best - but WATCH your photographer! Are they shooting with the sun behind them as much as possible? Or are they shooting into the sun?
Backlighting photos (shooting into the sun) can give you a beautiful, silhoutte image - if you are shooting for art and beauty. If you are an event photographer shooting for the entire event, this doesn't happen often, and when it does, it's for a specific purpose, not for an entire event.
Shade, sun, shade, sun - this can be tricky. There are times where the sun is on one side, and you must shoot down the middle or the other side. If the photographer can capture that exact moment when the dog is between shade and sun to look good - that can be great. But, like the top photo right, shade on most of the face and an eyeball - NOT such a good shot! Watch for lighting consistancey!
No one should claim to shoot action photography and think that every shot they get is amazing! When scrolling through you event images, be choosy. If the photographer has some good images mixed in with garbage, they are likely putting everything up to get you to buy. A professional will only put up what they believe is their best work and want you to see! Think about the photo - is it something the photographer should be proud of? If not, there is your answer to pro or wannabe. Check out image samples here.