[後「あと」]で => After V1, V2 N5
Time
〜がさいご(が最後) => if you do... negative result N1
Decisive (resolute decision)
たが[最後「さいご」] => Once A occurs, B happens N1
Information, Report
出す => to begin to; to start to; to burst into; ... out (e.g. to jump out, to carry out)​ N4