GOULI -
Flying at night, I would suggest that the fuel state display would not merit a great deal of attention. After all, you instinctively know what the flight duration of the aircraft is given the amount you took off with. So a quick glance every five or ten minutes is probably all the attention given to that particular bit of the display. If the fuel level graphic in the main tank shows fuel present and you assume that the supply tank pumps are switched on, then you probably don't even register the digital readings in the supply tanks.
You think we take LESS notice of fuel at night, even though we know from earlier discussion there are LESS places to refuel at night in the UK?
I NEVER assume the XFER pumps are on, they either ARE on or a caution (should) tell me they are not.
Also the graphic for the fuel is displayed in such a way (see previous photos) that you can easily read all 3 figures, not look at the main and ignore the supply levels.
And
The transfer pumps were switched on in the pilot's mind, except that in this instance it appears that a mistake was made and the prime pumps were the ones operating. A relatively easy mistake with identical switches all in a line in the same panel area.
I reiterate, you don't just reach up there and blindly switch a pump on and hope for the best! When you switch on a XFER pump you then look at the CAD to confirm the relevant caution has extinguished!
In this instance the reason why both XFER pumps were off is unknown, but IMHO the fact the prime pumps were on is significant.