Air India plane spotted in KLIA2

Air India is a full service airline and flies to KLIA 1 in Kuala Lumpur. Recently spotted an Air India plane in KLIA2, the low cost terminal primarily used by Air Asia and other LCCs.

Not sure why Air India plane flew into KLIA2- Maybe the air craft was temporarily exchanged with Air India express. Or is Air India cheating on Air India express going to KLIA2 without letting Air India express?

What do you think?