The 'corrugated' part attached to the plastic housing is what is called strain-relief and is intended to spread the stresses of bending the wire over a longer area than would happen without this extra bit. The usual breaking point of internal wire(s) is where the cable emerges from a rigid hole and can be bent over the edge of that hole. Strain relief grommets simply prevent sharp bending. Sometimes they are ultrasonically welded to the cable sheath and sometimes just slipped over. They don't form part of the circuitry, just there to protect the cable against sharp bends.
It appears as though this example has been over-extended at some stage - something which is oh so easy to do - and excess cable inside the unit has pulled through. If the unit still functions, there is absolutely nothing wrong with it other than cosmetics. Simply push the cable back in with a spot of superglue to fix it to the strain-relief grommet and all will be well. I believe that the problem is brought about by the way these things are described. "3ft coiled cable" could quite reasonably be assumed to stretch to 3ft when fully extended. The 3ft is the length of the cable cut from the reel before they put the curl in or make the connections. The curl takes up some of the length because it works by shrinking the sheathing on the inside of the coil. Once it's shrunk, that's it unless you reheat and stretch it. So "3ft coiled" rarely stretches more than a couple of feet before placing strain somewhere - and that somewhere is at the fixed ends. Then the sheathing pulls out of the strain-relief device.
In an ideal world, the strain-relief would be permanently attached and there would also be a metal ring crimped round the cable inside the unit. It's not an ideal world! I've just opened up boths ends of one Canon OC-E2, one Yongnuo OC-E3/s and one Pixel FC311 to check. Not a metal ring in sight; they all rely on the strain relief gripping onto the cable sheathing. There are differences in the thickness of the sheathing (though not the wires themselves as far as I can tell without desoldering) which make the Canon appear more robust but the actual wiring seems the same quality/guage. Given that the Canon unit cost me GB £40, the Pixel about GB £6 and the Yongnuo under GB £10 it's very difficult to justify the extra cost of the Canon. Especially for my intended use, which is in each case attached to a flash bracket where there is no possibility of over-stretch.
Eight_Blade wrote:
="Eight_Blade"]
You get what you pay for in everything.
Oh, if only it were that easy. I'd certainly agree that, broadly speaking, the quality is often reflected in the price. But there are plenty of people who shop only on price, assuming that top price equates with top quality. £40 Canon cord or £6 Pixel cord - same guage of wire, same strain-relief measures yet one costs nearly 7 times what the other does. More if you count my two trips into town to order and collect the Canon. They both do the job perfectly; if the Canon breaks I'll be very annoyed indeed, if the Pixel breaks I'll shrug and buy another. Another Pixel! Or Yongnuo! Not Canon.
If it still works push it back in with some glue on it as others have said. 
