Thanks slbaumgartner, this is what I thought too.
Can an admin maybe move this to the 'Report a Bug' subforum?
Maybe some SU folks out there will notice.

Hi all,

I 've encountered this issue where when I am exploding a group, it causes one of the Faces to lose its material, although it doesnt belong in the group.
Is that an expected behavior, or is this a bug?

Btw, the reason I am inserting each face, via a group that I explode, is because some of these faces might have holes, and carving out the holes, and then exploding the group is the most robust way I 've found so far that works.

Thanks,
Yanis

Code snippet:

inner = [[211.304795230314, 59.3387335473855, 144.121274015103], [198.016313479612, 93.8459200290483, 144.121274015103], [198.016313479612, 93.8459200290483, 209.586476052542], [211.304795230314, 59.3387335473855, 209.586476052542]]
outer_right = [[123.368393800971, 287.689711452616, 222.214015434512], [124.599206984753, 284.49356753989, 222.214015434512], [124.599206984753, 284.49356753989, 7.04087985299685], [123.368393800971, 287.689711452616, 7.04087985299685]]
outer_bottom = [[123.368393800971, 287.689711452616, 0.0], [123.368393800971, 287.689711452616, 7.04087985299685], [124.599206984753, 284.49356753989, 7.04087985299685], [278.931403899607, -116.27229864223, 7.04087985299685], [280.16221708339, -119.468442554957, 7.04087985299685], [280.16221708339, -119.468442554957, 0.0]]
outer_left = [[278.931403899616, -116.272298642254, 222.214015434512], [280.16221708339, -119.468442554957, 222.214015434512], [280.16221708339, -119.468442554957, 7.04087985299685], [278.931403899607, -116.27229864223, 7.04087985299685]]
outer_top = [[121.306929034951, 293.042869957925, 227.414539710024], [201.765305442185, 84.110634448818, 323.731055308166], [282.223681849419, -124.821601060289, 227.414539710024], [282.223681849419, -124.821601060289, 222.214015434512], [280.16221708339, -119.468442554957, 222.214015434512], [278.931403899616, -116.272298642254, 222.214015434512], [278.931403899616, -116.272298642254, 227.414539710024], [201.765305442185, 84.110634448818, 314.768300386351], [124.599206984753, 284.49356753989, 227.414539710024], [124.599206984753, 284.49356753989, 222.214015434512], [123.368393800971, 287.689711452616, 222.214015434512], [121.306929034951, 293.042869957925, 222.214015434512]]

# place a textured inner face
temp_group = Sketchup.active_model.entities.add_group
inner_face = temp_group.entities.add_face inner
material = Sketchup.active_model.materials.add "Test Material"
material.color = 'red'
inner_face.material = material
temp_group.explode

# place bounding faces
temp_group = Sketchup.active_model.entities.add_group
outer_right_face = temp_group.entities.add_face outer_right
temp_group.explode

temp_group = Sketchup.active_model.entities.add_group
outer_bottom_face = temp_group.entities.add_face outer_bottom
temp_group.explode

temp_group = Sketchup.active_model.entities.add_group
outer_left_face = temp_group.entities.add_face outer_left
temp_group.explode

temp_group = Sketchup.active_model.entities.add_group
outer_top_face = temp_group.entities.add_face outer_top
temp_group.explode

# inner_face has lost it's material
inner_face.material.nil?