Blizzard's messed up caps are quite annoying. For example, the Owl from the PotM's spell (one version of it, anyway) has a higher than normal sight range. If you try and edit it, it will be capped at 1800. You can't copy-paste it to anywhere else. Only be resetting it to default can you get the higher than normal value.
Pip and Gizmo, and possibly Jonny, maybe you guys haven't noticed that some abilities use a 100.00/50.00/10.00 (100%, 50%, 10%) format as opposed to the usual 1.00/0.50/0.10 one.
Examples of 1.00 spells: Thunder Clap, for the attack and move speed reduction. Evasion for the % miss. Trueshot Aura for the damage increase.
Examples of 100.00 spells: Bash, for chance to hit. Pulverize, for chance to stomp. Critical Strike, for chance to crit.
You can tell which ones are which by the dynamic tooltips. Compare:
Trueshot Aura: Increases base ranged damage by <AEar,DataA1,%>%.
Critical Strike: <AOcr,DataA1>% chance, <AOcr,DataB1> times normal damage.
Note how the extra % is added inside the dynamic tooltip tag that multiplies the value by 100% to get the readable one. Whereas stuff like Bash just use the value itself.
So to sum up, my theory is that Blizzard used a 100.00/50.00/10.00 format for the Defend ability, but whoever made World Editor capped it to the range that 1.00/0.50/0.10 abilities typically use.