The officers had a lot of time on the department but they obviously were out of their areas of expertise. Castle doctrine means if they barged in unannounced in the dark that the dude could have unloaded on them with an AR-15, killed them all and not get convicted. Nobody sane does no knock warrants today. Unless they observed that they never leave home, they could have waited for them to leave the next day. Stakeouts work better than forced entry 99% of the time for a petty dope case like that.