White Cloud Mountain Minnow

Question
Afternoon,
I am asking a question 'after the fact' because my white cloud has now died but I want to understand what I might have done and what I should have done.
My tank is a 30 litre bio-orb well established and completely cycled. It was occupied by 2 white clouds (just 1 left now!) and a red cap oranda. All the fish are just under 3 years since purchased.
I feed the fish flake, peas from time to time and freeze-dried bloodworm (usually once a week). The white cloud that died was a voracious eater and frequently took worms that I thought too long for it, but it always seemed to manage. However, last week the white cloud took another long worm (it had a bit protruding from its mouth) and a couple of days later was bloated up and couldn't swim to the top of the tank (although it tried). A couple of days after that it was lying around at the bottom of the tank and yesterday it was dead on the decorations looking like it had burst.
I was wondering if the desire to wolf down an over-sized bloodworm gave the opportunity for bacteria to enter the fish and do their terrible work inside it?
Is there anything I could or should have done and is there anything I need to do to protect the remaining fish? I want to do the job right but I also accept that their is a natural ending to all things and there is nothing that can be done about that.
Thanks for your help. Jonathan

Answer
I'm very sorry for my slow response.

The fish became bloated, and to put this as nicely as I can, it's stomach juices got out as a result and digested the fish inside- out.

In the future, simply make sure you are not over feeding your fish, and that all food is small enough to be swallowed easily.