Game Mechanics: Z axis playing a huge partin AoE spells (maybe just spells?)

[Ashintar]

While quadding giants in Eastern Wastes today I noticed that the Z axis placement is playing a huge role in the distance check.

I rooted a giant and levitated up high above it, casting Pillar of Flame and taking /loc checks here is the output. I wasn't high enough to play a quadding wizard when Velious came out the first time, but this distance check seems out of whack?

[Mon Mar 03 14:21:15 2014] You say, 'STARTING TEST'
[Mon Mar 03 14:21:15 2014] A frost giant tries to hit YOU, but misses!
[Mon Mar 03 14:21:16 2014] Your Location is -4440.59, 4236.50, 147.66
[Mon Mar 03 14:21:18 2014] A frost giant tries to hit YOU, but YOUR magical skin absorbs the blow!
<Getting Giant’s Location Above>

[Mon Mar 03 14:22:03 2014] You say, 'Start of Z axis AoE test using Pillar of Flame'
[Mon Mar 03 14:22:03 2014] Your Location is -4393.70, 4234.49, 192.56
[Mon Mar 03 14:22:03 2014] Your target is out of range, get closer!
[Mon Mar 03 14:22:04 2014] Your Location is -4393.70, 4234.49, 192.24
[Mon Mar 03 14:22:04 2014] Your target is out of range, get closer!
<too high>

[Mon Mar 03 14:22:06 2014] You say, 'Start of Z axis AoE test using Pillar of Flame'
[Mon Mar 03 14:22:06 2014] Your Location is -4393.70, 4234.49, 190.37
[Mon Mar 03 14:22:06 2014] Your target is out of range, get closer!
[Mon Mar 03 14:22:06 2014] Your Location is -4393.70, 4234.49, 189.92
[Mon Mar 03 14:22:06 2014] Your target is out of range, get closer!
<too high>

[Mon Mar 03 14:22:07 2014] You say, 'Start of Z axis AoE test using Pillar of Flame'
[Mon Mar 03 14:22:07 2014] Your Location is -4393.70, 4234.49, 188.81
[Mon Mar 03 14:22:08 2014] Your Location is -4393.70, 4234.49, 188.55
[Mon Mar 03 14:22:08 2014] You begin casting Pillar of Flame.
[Mon Mar 03 14:22:08 2014] You can't use that command while casting...
[Mon Mar 03 14:22:10 2014] You say, 'casting'
[Mon Mar 03 14:22:12 2014] a frost giant was hit by non-melee for 952 points of damage.
[Mon Mar 03 14:22:12 2014] A frost giant is immolated in a pillar of flame.
<finally able to cast>

[Mon Mar 03 14:22:19 2014] You say, 'Start of Z axis AoE test using Pillar of Flame'
[Mon Mar 03 14:22:19 2014] Your Location is -4393.70, 4234.49, 178.25
[Mon Mar 03 14:22:20 2014] You begin casting Pillar of Flame.
[Mon Mar 03 14:22:20 2014] Your Location is -4393.70, 4234.49, 177.95
[Mon Mar 03 14:22:20 2014] You can't use that command while casting...
[Mon Mar 03 14:22:21 2014] Your spell is interrupted.
[Mon Mar 03 14:22:25 2014] You can no longer levitate.
[Mon Mar 03 14:22:25 2014] You were hit by non-melee for 1 damage.
[Mon Mar 03 14:22:25 2014] YOU were injured by falling.
[Mon Mar 03 14:22:26 2014] Your Location is -4393.70, 4234.49, 150.15
[Mon Mar 03 14:22:29 2014] You say, 'GROUND'
<hitting the ground again>