It's not until they manage to get out that you find out about it.
My Darwin got out the front windows 3 times before I twigged how it was happenning.
First time I assumed that I'd left the window open
Second time I was sure it was Shut, Third time I was positive,
Turns out he'd learned to nudge the bottom locking bar, then nudge the handle and bunt the window open.
Cost me £170 in dog wardens fees.
I screwed the windows shut.
They are very tenacious, and resourcful when they want to be.
Don't be embarrassed by being outsmarted by a Husky