To make the hot honey sauce, combine the honey, vinegar, red pepper flakes and garlic in a small saucepan, whisking to combine. Bring to a simmer over medium low heat until the mixture thickens and reduces by about half, about 10 minutes.
Remove from heat, strain the garlic cloves and red pepper through a fine mesh strainer. Set the hot honey mixture aside in a small bowl and let cool.
Preheat the grill to about 400ºF (200ºC). Brush the grates with a bit of vegetable oil to prevent the chicken pieces from sticking to the grates.
Generously season the chicken legs with salt and pepper. Arrange the chicken legs on the grill skin side down on the grates and close the lid. Grill covered, for 15 minutes.
Brush the chicken with the honey mixture all over while on the grill. Continue to grill the chicken legs, turning every 10 minutes until the chicken is cooked through, about an additional 15 to 20 minutes. The chicken legs should be evenly browned (it’s ok if the honey caramelizes on the skin) with an internal temperature of 180ºF (82ºC).
Remove to a cutting board and let stand for 10 minutes. Drizzle with the remaining hot honey glaze and serve.