yeah, i just noticed that too. i dunno why they said it was a little loose as you have to really force that sucker on the inlet barb. if anything, it'll be even more loose by replacing it with a 1/2" barb. it was a lot easier putting the tubing in the DTek Pro Core, Maze4 GPU Block, and DTek WhiteWater 1/2" barbs than it was with the eheim inlet barb.
check out the picture at the end of
this article.
[edit]
oops, you said outlet, not inlet. yeah, it is looser/smaller compared to the 1/2" barbs. i tried to find a replacement for it but couldn't find any fittings that would make the outlet 1/2" ID at Lowes or Home Depot (they only had 3/8" ID fittings). you can pretty much stick the outlet barb into the inlet barb. i dont know who's bright idea it was to make different fitting sizes for in/outlet.