I just caught wind of this brother. Let me guess was it the t400 you were pinning? It is our only product we know that has a slight bite to it. Some people are okay with it some get bit. We make no bones about this as most t400 will have a bite. if not.. then it could be as you said the needle or how you store your gear. In all out years we have never had complaints about any of our products except the t400 and our R&D department does the best they can to come up with a formula to make the t400 as painless as possible but some are just sensitive to it.
No it was a bottle of Sust I had been using already... So I know it's not the gear. Like I said it dropped into the teens one night and it was in the bathroom with the window open. It may have crashed a bit and I didn't look at it first.
So in no way do I see this as the gear, again It was a bottle of Sust I was half way through.. So I'm thinking it got too cold or decided to play "let's jerk the needle all over the place and see what happens" I'm sure it's the fact I kept accidentally moving the pin all over the place.