When running a command block which contains a selector based on a scoreboard value (for example @a[score_aObjective_min=0]) the command block can not be run by redstone power, whether run by redstone dust, a redstone torch, or a redstone block. The output box will still contain the output from before, which will always be the command itself from when it was set.

To reproduce:
1. Get a command block, and enter a command that includes a selector which has a scoreboard based condition (f.e. /tell @a[score_Objective_min=3] Hi)
2. Run the command block using any form of redstone.
3. Note how the command block won't run.