What do you believe Vader was thinking

When he threw the Emperor down the fusion shaft? I always like to think, as Vader was watching the Emperor kill his connection to his wife, the reason I turned to the dark side is to protect my wife from death, now the Emperor is going to kill a connection I have left to her?

The reason Vader turned to the dark side was to save Padme, so seeing a connection to her being murdered brought Vader to take action and kill the Emperor