Jan, you must call the police. You can deny that it was you who called. Just call the police and explain about the smell.
Jan, the fumes from meth making can be dangerous to inhale, honey. You can't keep inhaling this, if that's what it is. I've read about it many times. Shoot when they find one in our area they evacuate the entire area until it's cleaned up due to the potential for explosion and the dangerous fumes.
I don't think you have any other choice but to call the police. You can do it anonymously. Please hurry on this one, ok? If you do it while the fumes are in the hall, the police will know right away if it's meth.
If it's not meth then cool.

Also, your neighbor would have to establish a PATTERN to sue for harassment...one call to management and one to police over the same issue in the same week wouldn't be considered harassment. I would bet good money on that.
Please let us know.
KD