Silverfish only get a scoreboard value if they are outside of a block

SOLVED!!!

I have the following commands:

1)

/scoreboard players set @e[type=Silverfish,c=1] test 1

2)

/execute @e[score_test_min=1,score_test=1] ~ ~ ~ testforblock ~ ~ ~ air

comparator between these

/tp @e[type=Silverfish,score_test_min=1,score_test=1] ~ ~-1000 ~

/blockdata ~ ~ ~2 {SuccessCount:0}

What happened:
As long as the silverfish I summon simultanuously with

/execute @e[type=Pig] ~ ~ ~ summon Silverfish ~ ~3 ~1.2

are inside a block (fence) they will not be teleported.

As soon as they move outside, they are.