Probably a plumber with the "bore scope" camera could determine if the pipe was properly straightened. Replacement would be the far better option. Based on the photo and how much it shows being done after the pipe was bent, I doubt that any repair was done.
You could ask the fellow exactly what he did, listen carefully to his explanation and then later have the scope inspection.
"Trust but verify" Ronald Reagan.

Flashlight and a mirror - cheaper than paying a plumber.

Since this is the exhaust for a kitchen hood, I would not worry about having some wrinkles in the duct work. If the duct is the correct size for the fan, then it should work fine.

Thanks for your replies everyone. I also got a few replies in the Home Repair forum. I'm new to all this and not sure if it's ok to post the same topic in various forums or not. I was not sure where best to post and it seemed like two appropriate places. Please bear with me until I learn the proper forum etiquette and in the meanwhile thank you for your replies!

One reply mentioned I should seal that hole from the electrical work in the ceiling. It's already closed in now and I didn't seal it. Should I be worried?

Use the video function on a smart phone and tape it to something to send it up inside the vent if possible. If you can accomplish it and it is smashed you also have recorded the evidence.

If it is the same as your photo I am not quite as worried about the duct as I would wonder what else there is that you do not know about.

If you can reach up with phone in hand far enough to get to the straight section of pipe regular pics work wonders.

The original hvac installer only cut 3x3-3x6" holes in the floor for my returns with 7x14" return grilles on the wall and I had mysterious return issues. I took the grilles off and shot photos down and about blew a gasket. I had to pull all of the panning out in the basement and in some areas open up the areas with a coping saw by hand. Cutting through a 2x4 and subflooring with a coping saw over the sewer drain line was not pleasant..

"One reply mentioned I should seal that hole from the electrical work in the ceiling. It's already closed in now and I didn't seal it. Should I be worried?"

People double posts in other forums all the time. Its not a problem unless you get conflicting advice.

If the kitchen is on the first floor of a two story house, then I would not be very concerned about the hole in the ceiling. But if this is a ranch house, then cold air will come through from the attic above. In that case you could go into the attic and seal it from above.

I feel double posting is a problem... if a good idea pops up on one forum, the readers on the other forum won't befit.

If double posting and made it known in BOTH forums where to find the other thread would help.

I'm sure he just boxed it in, as-is. Sloppy work but I wouldn't worry too much about it. There are way worse things than that in your house...............

I wouldn't worry. There are far more things in the world to worry about. The dents might be sloppy but they aren't going to affect the exhaust in any material way. And as stated, if the electrical hole is between floors, so what? If it goes to the attic and you can reach it, then you might want to plug it up a bit.

Thanks everyone!

@ sktn77a - You mentioned..."there are way worse things than that in your house..." Please tell me what else you are seeing...thanks!

Sorry, nothing visible. I was being cynical. There ARE worse things in your house......... but you haven't found them yet!

Hopefully, there aren't any holes in the ducting and you will not be relying on the duct to vent greasy air. If you are just using the hood range exhaust to vent hot air to keep your kitchen cool, it should be fine. Its when grease collects and drips is when you might have issues. I dented my own when I installed it since it was such a tight fit with weird angles. Enjoy your cool kitchen. All stove hood exhausts should vent to the outdoors. Those recirculating hood exhausts are a joke.