Unfortunate restaurant recommendation

The salmon was so overcooked it flipped over when my wife tried to cut into it

Never ever would I have thought one would have to "cut into" salmon.

Prawns still in the shell over linguine? ...really?

I hope they made some accommodation on the bill

Be sure to leave comments here--- https://www.ricksteves.com/forms/guidebook-feedback-form

Any guidebook is out of date before it is published. The recent Trip Advisor reviews are polarised - either brilliant or awful and few reviews in between.

In some cases, shrimp is cooked in a way that eating the shell is a treat. Epicurious:

"Yes, shrimp shells are not glamorous. They aren't particularly
appetizing. You could even argue that they aren't even food. But I am
here to assure you that under certain circumstances, they are
shockingly delicious, with a treasure trove of flavor and texture that
naked unshelled shrimp can't even match. And if you're tossing them
away, you're missing out. Here's what you need to know about how to
live that shrimp-shell lifestyle:"

https://www.epicurious.com/expert-advice/eating-shrimp-shells-recipes-tips-article#

I can assure you that these prawns were not a treat!
What little meat I was able to remove from the shell and eat was tough. I can only guess that the prawns were overly cooked or frozen for a long time or had suffered some other mistreatment..

This is why I prefer to look at Google and Yelp reviews versus just Rick Steves' restaurants reviews. Better to see several opinions/reviews and determine if there is a trend, whether positive or negative.

It seems like you were offered a replacement but chose not to order. IMO this website leaves no room for the restaurant to tell its side of the story. I guess I wouldn't take the chance and eat there but I would think that Ricks recommendation should carry more weight.

I just realized that "Le Bistrot" in Edinburgh is a "French" resturant. I wonder why Rick would be recommending dining in a French resturant is Scotland.

https://restaurantguru.com/Le-Bistrot-Edinburgh
Most of the "reviews" are 4+ of 5 but one "one star" reviewer agrees with OP:

Andra Luciana Chizeveter

1 stars

2 months ago on Google

Husband got food poisoning from the prawn and linguine dish…I looked at the reviews and I see the restaurant serves so much sea food
and people are very satisfied, I bet we had really bad luck, it only
takes one prawn. We had just arrived in Edinburgh and after checking
in the hotel we went sightseeing, didn’t eat anything before, ate at
Le Bistrot - we both had the Onion Soup - which by the way is NOT
French Onion Soup with cheese and bread,

actually, Edgar I don't think that the review you chose has anything to do with the complaints made in the OP. I saw nothing about getting sick.

I too see that the OP was offered and refused a replacement.

"the OP was offered and refused a replacement"

Not much solace there, if both original meals missed the mark, little hope the replacement would be any better. If the post is to be believed, I would just want out of the place, pronto.

Line 5 in original - "I elected not to order a replacement meal ..." sure sounds like the restaurant tried to fix this.

Two notes--This is a new entry in the RS GB 23rd book, it was not in the 22nd edition. And given the comments made in that edition, along with other RS books, I find it rather surprising that a restaurant smack dab in the middle of the tourist conga line on the Royal mile is being recommended, as he is always recommending get a block or two off the tourist area for better food and prices.