Cook the bacon over medium heat in a 12-inch nonstick skillet, stirring frequently until crisp, 6 to 8 minutes. With a slotted spoon, transfer the bacon to a plate lined with paper towels.
Pour off and discard the bacon fat from the skillet. Heat 1 Tbs. of the oil in the skillet over medium heat. Add the bread and cook, stirring, for 5 to 7 minutes, until crisp on the outside and lightly browned. Transfer to the plate with the bacon to cool.
Coarsely chop the garlic and sprinkle with 1/2 tsp. salt. Using the flat side of a chef's knife, mash the garlic to a paste.
Heat the remaining 2 Tbs. oil in the skillet over medium heat. Add the garlic paste and the shallot and cook, stirring, just until the garlic is fragrant and the shallot softens a bit, 30 seconds; don't let the garlic brown. Transfer to a large bowl, add the parsley, vinegar, 1/2 tsp. salt, and 1/4 tsp. pepper and stir until well combined.
Add the romaine and tomatoes to the bowl and toss with the dressing. Add the bacon and croutons, season to taste with more salt, and toss again. Serve immediately.