Dragon won't die + Some audio bugs

Hello Dragon Age Team, I'd like to report a bug while doing some quest (https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-xtf1/t31.0-8/11417746_1005569382787909_8246633716706293557_o.jpg) there's the link. I killed the dragon but it won't die, it just stay still and some random lightnings struck him, I restarted the game now I have to kill it again oh and by the way before the bug happened Varric was dead and when Vivienne threw the last hit, Varric suddenly talked while he's dead which is kinda funny. I played it on PS4 and sometimes the game audio will be gone while playing. Thanks in advance DA Team!