I believe according to their privacy policy and from past press statements deleting the data does trigger a real wipe of the data but I think there is a up to 30 day delay (not sure exactly) (wiping data from thousands of servers is actually kind of difficult).

If your threat level is NSA/nation state then this isn't good enough since they probably could get a copy before Google deletes it but it is probably enough to be useless for low level LE.