First off, this is not an authentic Sinangag. When I discovered this fried rice dish, I also discovered that every household in the Philippines has its own spin on the traditional breakfast dish. Some use garlic and rice only. Some add soy sauce.
Many serve the vinegar sauce on the side only. As I played with variations on the recipe, I felt the rice needed a bit liquid while stir frying. I hit upon this approach after misreading a recipe in Saveur (http://www.saveur.com/article/recipes/filipino-garlic-fried-rice-with-vinegar-sauce-sinangag). Adding the sauce to the stir fried rice mellows the vinegar and garlic a bit, while incorporating heat from the red chile flakes.
If you prefer, omit the sauce while stir frying. You’ll still need a good amount of garlic, remembering to reserve some for a crunch topping. It will be delicious either way.