Poor guy ! That would tick me off too especially shaving so close to the skin and seeing him shake.
To let you know you aren't alone - many of us have had a bad groomer experience - i used to stop in and watch without my yorkies to see how they operated but after only a few trips to a couple of groomers and some BAD haircuts - I decided to do my own too.
It can be easy to groom yourself (we don't have showdogs so it's not imperitive they look perfect right?)
you can can do a little at a time and cut as much or as little as you want - if you mess it up - it'll grow back....they'll act up maybe but at least you know they're safe and so do they- eventually they'll learn it isn't so bad to get a little haircut. Mine are really good about it now.
One thing about some of these places is you really don't know how they treat their dogs - Alot of groomers are just ROUGH
If anyone DOES go to a groomer - make sure they don't use drying cages - ...also - sometimes they medicate dogs without telling people. I don't think it's common but have heard many dogs act 'funny' after being at a groomer.
his hair will grow back and just show him lots of love but don't fawn over him - he'll forget what happened but if you show how stressed you are - he'll feel it too.....just give him some lovin and a sweater if he gets cold