Singapore is a FINE country.

Ah well, most probably 4 months ago he scanned when leaving but there was an error or sort. And he missed it or ignored it (don't wanna assume).

2 iphones gone

for those who will always enter/exit using car/motor...

not applicable for those who always fly in...

for me, i've driven once in sg, and thats all. next time i will just fly in

Look at it from a bigger view, its SG fault for not improving their system. And its good money for them, maybe thats why they never bother with it. 

But technically, its still individual fault for not checking properly.

Yeah. Had similar experience. Luckily i remember to scan the card.

Can just buy new card?

Malaysia better, can just buy new TnG card.