Interesting photo. That straight line across the top looks like it may be an area of weakness. Instead of something chewing through hardware cloth I'd expect something to tear it, similar to what happened in the attached thread. I don't know what part of the world you are in or what your potential predators are.
Dog Vs. Hardware cloth... | BackYard Chickens - Learn How to Raise Chickens
Patch that section of hardware cloth with other hardware cloth to keep small predators out. Then use a heavier wire mesh on top of it to keep larger predators out. I used a 2" x 4" welded wire mesh fencing but can't remember what gauge it was. Fairly heavy.
Your connections can be your weak point. Make sure it is firmly attached so they can't just pull it loose.
People can go years without a problem showing up. You got hit within 12 hours. That could have been something going after the chicken feed and not the chickens. That just shows how inconsistent this stuff can be. A motion activated game camera could be enlightening but I never got one.