Red, the Tour was on the line. It was either go for podium or the win.
The alternate outcome that you are asking is using the team members more properly. Put them on the red. Once they were out ride hard yourself. Why wait until Froome arrive to the group for the attack. If the others didn't want to cooperate with him then Bardet had the choice to slow down and save himself for the podium or keep going a la Cadel in 2011 Tour. My 2 cents!
The alternate outcome that you are asking is using the team members more properly. Put them on the red. Once they were out ride hard yourself. Why wait until Froome arrive to the group for the attack. If the others didn't want to cooperate with him then Bardet had the choice to slow down and save himself for the podium or keep going a la Cadel in 2011 Tour. My 2 cents!