Once the flat reaches 190 degrees, it is ready for slicing after a rest. At this time separate the point and prepare to make burnt ends with it ! The point was tough because it was not yet done. It is a thicker piece. BTW, where is the Q-view??
Mike
Mike is correct about the point not being done, as far as IT, I cook most of mine to well over 205 and they slice just fine (cooking at home or for comps), however I rarely use IT as a barometer for doneness anyway, I use the toothpick test. The point will typically take at least another 2 hours, sometimes 4 before it is cooked and tender. The higher amount of fat in the point section makes for not only some of the best sliced meat you'll ever eat, but it also requires a bit more cooking or at the very least higher temps, hence the reason to place the brisket on your smoker with the point end facing the firebox or the hotter are aof your pit. Never, ever, place your temp probe in the point of a brisket, with the fat content, you'll never get a correct reading of IT. The point is also toothpick tender way before the flat, but trust me, it's not done.
I have started doing most of my briskets this way, I completely separate the point and flat sections, allowing me to cover more of the meats surface with more rub, exposing more meat to the heat, speeding up cooking and building more delish bark all over. If I cook the brisket as a whole, I do as SoMs stated, separate the point from the flat once the flat is done and throw the point back on the smoker or in the oven to finish it off.
Cooked this way, you will end up with slices from the point looking like this:
Better than a ribeye as far as I'm concerned. Of course I'm a Texas boy and brisket is king! When I do my briskets this way, I will typically smoke them both for the usual 4 hours at 250, but when I wrap, I leave the flat at 250 on the bottom grate in my pit, then move the point to the upper grate to expose it to a higher temp, typically 275+. This will help with getting both meats to finish near the same time. All that fat needs to be rendered down to get the most succulent piece of meat you can. I think anothe rmember here, Eric (forluvofsmoke) has a thread on cooking briskets this way if you want more info. I ran across it after I had started doing mine this way earlier this year, good read.