The thing is the doctors the Texans have are probably pretty good. BUT the key here is who do they work for? The team doctors work for the team, not for the players. As such, they are going to say things that the team wants released. If the team does not want the doctor to say or release info they won't. If they tell the doctor to say "slight leg injury" when it is infact a major one in order to not let another team know, they will do that.
Dr. First and Dr. CND are independent of the team and as such can be more honest and critical when it comes to medical news. I don't know Dr. First, but Dr. CND has done a fantastic job in explaining and detailing injuries for the rest of us!