Actually, by searching with !g, you’re leaking your info to both DuckDuckGo and Google, instead of just Google.
If you want to do Google searches without leaking your data to Google, you could use Startpage.com, but personally I don’t trust Startpage more than Google.
I'm not sure about the "without leaking your info to Google" part, there. All it does is forward you search query to Google as if you'd entered it on google.com. There's not really anything DuckDuckGo can do about that.
I got in the habit of just appending this to many of my queries in time sensitive situations, as if by reflex, negating the purpose (I default my search engine to DDG so !g is the fastest way to Google for me). I am having a hard time breaking the habit.
If it runs the query through DDG's server side, then Google would just see at as an anonymous query along with a million other anonymous queries coming from DuckDuckGo's servers.
Unfortunately, that's NOT what they do. Instead, they just forward you to the google search result, which is pointless and stupid.
Not so. The point is that you can set DDG to be your default search engine, and put !g anywhere in the search string to search google in case you need it.