〜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
[後「あと」]で => After V1, V2 N5
Time
最中に => while; during; in the middle of ~ N3
[最中「さいちゅう」] => In the middle of A N3
Time, Situation