Rough Ground or Bounce Can Unlock Spoilers
On an early flight in a Junior, the first behind a Pawnee, I ballooned on takeoff. The [slightly over] correction bounced me off the ground, but no more oscillations.
Once we were both in the air, I noticed the handling was poor and saw the spoilers had come out - and promptly closed them.
We train devout adherence to the checklist, but we do not train for the rare but humanly inevitable times the spoilers come out or the canopy comes unlatched.
I saw an L-33 written off when the pilot would not let go of the unlatched side opening canopy to use spoilers on short final. He used sideslip to get down and in the moment did not realize that a sideslip against the opening would have held the canopy down hands free.
I saw a Jantar with a shattered canopy make a dodgy circuit to a cross runway when there were perfectly good fields ahead.
With a CG hook, I keep a hand on the release for the entire duration of the launch except when I have to change flaps.