Lay the bacon slices on a rack on a baking sheet. Bake until crispy, 15 to 20 minutes. Set aside and keep warm.
Make the hollandaise mix according to package instructions, using the clam juice and milk with the 1/4 cup butter. Whisk in the prepared hollandaise. Set aside and keep warm.
Put the pesto into a small bowl and mix in the herbs. Thin it with a little water.
Melt the remaining 2 tablespoons butter in a medium skillet over medium heat. Cut the croissants in half and cook them in the butter until they are nicely browned. Warm the crab in the same pan.
Bring a medium skillet of water to a very gentle simmer and add the white vinegar. Crack an egg into a small dish and carefully slip it into the water. Cook for 2 to 3 minutes, depending on how hard or soft you like your yolk. Remove with a slotted spoon onto a paper-towel-lined plate. Continue with the rest of the eggs.
To assemble: Put 2 croissant halves onto a plate. Cut 4 bacon strips in half and lay the strips on top of the croissants. Place 2 poached eggs on top of the bacon. Place a spoonful of crabmeat on top. Cover with hollandaise and sprinkle 1 teaspoon chopped olives over each. Drizzle the pesto around the plate.