You know, these swat teams do make mistakes: false tip, wrong address, etc. If they make a mistake, chances are it will be non-users, like you or me, they are doing a dynamic entry on... except as law abiding citizens we have less reason to think the police would be knocking our door down.
Imagine someone knocks your door off it’s hinges at night without any real warning... what is your first instinctive reaction? Do you want to assume its the police and if so what if it is armed criminals pretending to be police? If police can get away with blowing a junkie away within 5s of doing a dynamic entry for holding up a golf club, they aren’t any less likely to do it to us just because they were at the wrong house.
Authorities make mistakes, abuse their powers and otherwise act unjustly towards the citizenry. This guy may have been stupid for using meth and pot, but shrugging off his right to defend his home means you give up your right to do the same.