It's one of those "suspiciously specific denials"

They didn't delay the release because of law enforcement investigation, it doesn't say they didn't delay the release. There's a whole host of reasons besides "law enforcement investigation" to delay an embarrassing release, including "I don't wanna"

The quote is: "We have not delayed this notification as a result of any law enforcement investigation"

The obvious example here would be if the NSA or other agency that isn't law enforcement led the investigation.

But further abuse of the English language reveals a different conclusion. This was not delayed as a result of any law enforcement investigation. It could have been delayed as a result of a specific law enforcement investigation. Furthermore, the word "result" implies that it is tied to the conclusion of said investigation(s). It could in fact have been delayed because of a pending law enforcement investigation.