scoreboard command interacts wrong with execute

Running the command:
"/execute @e[type=Skeleton] ~ ~ ~ /scoreboard players set @e[c=1] Score 0"
will set the players Score score to 0 even when it is run by a commandblock

Preconditions:

• /scoreboard objectives add Score dummy
• /scoreboard objectives setdisplay sidebar Score
• /summon Skeleton ~ ~ ~