Mistake number 2?

Upon returning from my first fishing outing, I needed to remove the line from the Dunlop reel, and replace it with some new line.
Now I have always put the spool of new line in water before winding it on the spool. One, it gives me tension, and two, the water lubricates the line as it goes on allowing it to seat better. Or at least that is what I thought. I had always done this in the past, and never had problems.
This time however. . .
I was near the end of filling the spool and I noticed the reel getting stiff. I looked over it but could see no reason as to why this was. I pressed the button on the end to get the spool off the reel, and it would not come off. Eventually, it sort of went click but in a soggy way, and something looked odd. I then noticed what I was seeing.
This.

Somehow, the line had split the spool. Whether it be through too much wind on tension, or some other reason, I don't know. I have since done 2 other reels in the same way. One with the same line, and the other with 15lb line and not had any problems with them.
The reel cost me £6 from Dragon Carp direct, so I'm not bothering sending it back. But as the reel only came with one spool, its bye bye reel.

It also meant I had to replace the reel. So I spashed out a bit more and got this:

A Shakespeare mach 2xt.
It came with 2 alloy spools. One deep, one shallow, and a graphite spool. I'm quite liking the feel of this reel, and I am tempted to replace my other float reel with another one. Someone said it wouldn't be long before I become a tackle tart, and I feel they aren't wrong.