So I think I finally made a decent brisket, however something odd happened a few minutes into cutting it. To explain, I use a WSM and prepped the meat (a 5 lb point) last night with a rub and injectable marinade. I put it on at 6 in the morning and got it out at 5 this evening. I cut it after a 10 minute cool down period. Initially it was very moist and tender, but about 20 minutes later it is now dryer and less tender. I was wondering what I did wrong. It still tastes very good, I just don't know what I did wrong.