Is that 1 wire.hose?
I never run off the reel, for that reason. It happend to me once. I have two 100’ and one 50’ and just use what I need. I never run chems in it either. 2 years strong.
This was the second time I’ve ever run off the reel. Go figure. I’ll be ordering an unloader block this evening to mount at the edge of the trailer…along with more hose 
Get yourself a k7 or some other flow actuated unloader while you are at it. Much easier on all of the equipment, especially hoses.
When I first got into this business, I was told never to run off the reel. Always unwind all your hose before starting up. All I can say is coming on 1 year and never an issue. The one time I tried to leave some on the reel, it was like a newbie with a baitcaster. I was told on the reel, when it tightens up is adds pressure to the underlying layers kinda of like a constrictor and will take some life out of your hose.
I have no idea what caused that. Have your hoses been run over before by a car or truck?
How old was that hose? Looks about at the end of it’s life anyway. I run mine on the reel anytime I can, unless I’m already close to the end. But I replace mine every year and relegate them to extra and backup status.
