Not an over reaction when you go ask her what her new safety procedures are to ensure he doesn't escape. Explain you trust her but after that experience you both endured as she would have felt guilt and panicked by the situation aswell, you are just wondering how he would be kept safe since next to a major road. Also explain you are pregnant and really can't deal with worrying and stressing unnecessarily so just need reassuring.
If you and your dog like and trust this groomer, then you can work a way around it. I would ask that if the groomer takes them out the door they always use a lead and harness? I'd have thought that would be common sense for most set ups anyway!
Maybe ask can you stay whilst they are groomed?
Just ask for a lead on to take him out. Surely that should be standard?
i wouldn’t say over sensitive or over reacting . all i would say is if you can’t relax while your pup is there and it’s no longer the best fit , find another groomer which makes you comfortable . Nothing wrong with moving on if you feel like it’s a matter of safety for your pet x sadly accidents do happen and once they do it’s hard to come back from that fear you felt in that moment . it’s ok to feel like it’s not going to work out x