There is like 6 total versions. 2 of the 28-80s but there is probably not much difference. Tokina's CAs are generally purple. It's not CAs but it looks like reflection or diffraction from the filter (from both shots). I do not think it is the lens but not to say you were at just the right angle for that to happen.
Due to Tokina's coatings I have found there is more reflection than other lenses. I have found you really need a higher end filter that is specially designed to eliminate reflections. I use "Hoya HMC Super" and it works well.
I think you have a mixture of a odd light source, JPG/De Noise, over saturation and some reflection from the filter and probably some smoke or dust that diffuses and spreads the back light. I think you just stumbled upon that perfect mix of everything that can happen with any lens. If it was the lens only, the light on the left would have done something similar. I think any lens would have reacted the same or similar, Nikon or not. The Tokina IMO is 100x better than the 18-105.
Just from one picture, I wouldn't worry that the lens is not good. A good habit with any lens is to make sure back light sources are hidden and not shoot them straight on.
noxin - in your picture that is definitely the filter causing that. B+W or not, that is the filter for sure. I have seen that on my older filters without the advanced coatings and anti-reflective coatings that will cause the "Prism" effect.
Filters really can make a huge difference. For the "high end" filters, you generally can figure about $1-1.50 per mm. So around $70. I use either Hoya (SMC) Super Multi coated or the Pro1D filters. Never anything less. Those are the cheapest, highest end filters I have found. Kenko has some, but the actual good ones are in the $140 range.
I know a lot of people like B+W filters but I can't stand their terrible "naming" scheme where you can never know which version you are getting just by the name. In the past I have always had problems with color separation (like noxin's photo) and reflections. A friend of mine loves them, but he spends $180 for each 77mm filter.