O---------------K,
I'm still thinking you're cooking at way too high of temps, and as Dutch stated, meat that is allowed to temper or warm-up prior to cooking has less time to develop a smoke ring, due to reaching 140* I/T that much faster. To be fully cooked in the short time-frame you mentioned is not probable...167* in the point (thickest part) would probably translate to around ~180* in the flat (thinnest part). The flat would have been finished for slicing temps at that point (with most briskets, some need a bit higher). Here's where I have a problem understanding the finished temps: if the point was 167* and assuming (flat temp not specified) that the flat was at or near 180*, this is not possible with chamber/grate temps of 190-200* in this short of a time frame. It would also cause a very dry flat-cut of brisket, being it is pretty lean in the muscle, but would require many, many more hours to reach that finished temp.
I've made cured heat-treated semi-dried sausages with up to 3lb chubs which are cold, warm, then hot smoked. With 180* max chamber temp towards the end and I/Ts around 135-140*, the internal temp rise is extremely slow (painfully, to be more accurate), taking several hours to climb from just 135-140* to the finished temp of 160*, and all this is happening with meat that is already warmed through quite well. It all comes down to temperature differentials between the cooking chamber and desired finished internal temp of the meat: the higher the temp differential, the less time it takes to equalize; the lower the temp differential, the longer it takes to equalize.
That said, thermometer accuracy (translating to excessive chamber temps) and/or placement were not conducive to achieve proper cooking of the brisket per your finished temp reading. Chamber/grate temps where the brisket was positioned must have been way off the charts in comparison to what we refer to as low and slow, and this would also fall right in line with cooking at such a high rate that little or no smoke ring was developed...fast cooking = far less or no smoke ring.
Most analog thermometers do not tolerate abuse very well at all, and it doesn't take much to throw their accuracy right out the window. Vibration from vehicle mounted cookers being transported, as well as portable/patio models being hauled or moved manually in your yard, for example, and especially those subjected to shock from being dropped or stuck by another object should all be considered suspect for needing calibration or verification.
Aya8442005, here's where I'd start, if I were in your boat:
http://www.hi-tm.com/Documents/Calib-boil.html
Be sure that your thermometers are as accurate as possible. If they cannot be calibrated (non-adjustable), then you can make a note of how far off they are and add or subtract that amount from the thermometer reading to reach an accurate temperature (verified). If they do come out as still being accurate, then, I'd have to suspect a prep method such as application of a fat/oil to adhere the rub to the meat as being the culprit to lack of smoke ring development. Nothing else makes any sense to me at this point.
Type of woods used for firing or smoke wood will not kill the smoke ring, although some species may seem to generate a more pronounced smoke ring than others, and some produce a deeper, darker color on the bark, but none will prevent it from taking place.
Also, brisket is one the few meats that needs to be fully cooked to get tender, well above the 160-170* range with typical cooking methods. It's a very tough cut, from muscles that are used by the animal for locomotion with every step they take...lots of connective tissues/collogen. In order to achieve a tender brisket, it needs to be cooked slowly to allow for melting of these connective tissues, and if cooked too quickly, it will still be tough, regardless of finished temperatures and moisture content.
I don't know what else to tell ya, brother, but definitely start with the thermometers, then your prep method.
Good luck!
Eric