weapon mod mistake?

There was an update awhile back that made equippable items that weren't gold or green incapable of having perfect modifiers attached to them.
I just found a purple wand with a perfect, energy +5 ^50 inscription. I'm pretty sure this is the second one I've found like that. I was just wanting to point that out and bring the devs attention to it because I'm sure they would like to change it.

Purples can definately have a perfect mod. Golds will always have at least one perfect mod, usually the crappy one.

It depends on the range of the mod. If your choices are +4-5ar, you can most definitely get +5ar on a purple. Larger ranges like +20-30hp... I don't think you can see +30 on a purple.

Elonian weapons seem to be the exception to that rule. Inscriptable purple items can drop with perfect mods apparently. I've found a few myself.

I do runs in the tombs and from chests I get perfect mods on purps ( don't know if that really counts) and in FoW i get perfect mods on some of the purples that drop from spiders

You sure about that? Last night I got a gold offhand from a Desolation chest with +58 hexed/+9 vs. Neither of those are perfect.

Yeh, am always getting +5^50 mods from purps now

http://gw.gamewikis.org/wiki/Weapon_upgrade

Wiki is your friend....

Purples CANNOT have max upgrades in some cases(usually the better ones, i.e. Sundering, Health, HCT, HSR, and dmg bonuses on weapons[innate and Inscrip])

Only Golds can have max but they are not guaranteed too all the time.

It's not true that you get a guaranteed perfect mod on a gold, your suspicion is correct. While the mod range is shifted to near perfect, and that you have a higher chance of a perfect mod as a result there isn't even a guarantee you'll have all 3 mods (I believe 2 mods are guaranteed to appear on a gold, 1 on a purple).