Command blocks arent picking up the new nbt tags assosated with the new potion format

Command blocks arent picking up the new nbt tags assosated with the new potion format

was trying to fix a command module that stopped working in this snapshot. the command worked in previous version when it was

/execute @r[type=Witch] ~ ~ ~ /execute @r[type=ThrownPotion,r=3,rm=0] ~ ~ ~ /scoreboard players set @r[type=ThrownPotion,c=1] WitchAtt 3 {Potion:{id:minecraft:potion,Damage:32698s}}

using entitydata while a witch was throwing potions i got that the nbt format had changed to something like

{Potion:{id:"minecraft:splash_potion",tag:{Potion:"minecraft:slowness"}}

so I tried to fix the command by doing this

/execute @r[type=Witch] ~ ~ ~ /execute @r[type=ThrownPotion,r=3,rm=0] ~ ~ ~ /scoreboard players set @r[type=ThrownPotion,c=1] WitchAtt 3 {Potion:{id:"minecraft:splash_potion",tag:{Potion:"minecraft:slowness"}}

but it comes back as

Failed to execute '/execute @r[type=ThrownPotion,r=3,rm=0] ~ ~ ~ /scoreboard players set @r[type=ThrownPotion,c=1] WitchAtt 3 {Potion:{id:"minecraft:splash_potion",tag:{Potion:"minecraft:slowness"}}' as Witch