Once I did a lowpass as SLF on a LH 744 in BOM. We approached as usual, but then didn't land but went over the runway at about 500 ft. (No as nice as the 753 in TLS during the SMD, but similar) Once we were at a decent height, the captain came on and said 'the system was telling us that the landing gear was not down, so we made a low pass for the tower in BOM to take a look at it: yes, they are down. We will land shortly.'