"Sia lah" = Singlish/Manglish expression of incredulity or dismay.
(Can be used positively ["hot damn"], but not so here.)
It is derived from Malay 'sial' ("inauspicious", "having bad tidings", nowadays used as a curse word meaning "damn" or "dumbass") + the illocutionary particle 'lah' (used to provide emphasis, reassurance or as a command, best translated by stressing the previous word or italicizing it in written form).
Note that 'sial' is much stronger in Malay than it is in Singlish/Manglish.
"Sia lah" = Singlish/Manglish expression of incredulity or dismay.
(Can be used positively ["hot damn"], but not so here.)
It is derived from Malay 'sial' ("inauspicious", "having bad tidings", nowadays used as a curse word meaning "damn" or "dumbass") + the illocutionary particle 'lah' (used to provide emphasis, reassurance or as a command, best translated by stressing the previous word or italicizing it in written form).
Note that 'sial' is much stronger in Malay than it is in Singlish/Manglish.
We Indonesians sometimes used 'sialan' to curse. Kind of adaptation to the 'sia lah'