That doesn't make me feel better... They were guards that were there to protect a medical facility with unknown but likely friendly affiliations. Coulson did not follow protocol for the facility (he didn't know what it was, of course), ordered his men to break in and storm the building, armed. Any guard in that situation would likely follow the proper orders - shoot to kill. Coulson decided that his one friend - who's life was in danger as a direct result of decisions - was more important than these two fairly innocent guards that did nothing wrong other than protect the building they were instructed to protect from armed intruders that were unwelcome and unwanted. Dropped his likability down several notches.