Why can Canon shoot faster than Nikon? (exposure, not drive speed)?

So last week I was shooting badminton with Canon 7D with 24-70mm f/2.8 and I could shoot at
1/400, f/2.8, ISO 1250
and the pictures are PROPERLY exposed.

and yesterday I shot at the SAME PLACE under the same lighting with a Nikon D300s and 24-70mm f/2.8 and I could only shoot at
1/320, f/2.8, ISO 1250 and the pictures are UNDEREXPOSED by -1/3 stop

Why?

Added (1). No. It's indoors, it's in the gym. And I know that it's underexposed by 1/3 stop because it's looks underexposed and the camera meter said so. With nikon, it's at 0EV, with canon, its at -0.3EV

I have no clue unless the EV adjustment on the camera was set incorrectly

I shoot next to Canon shooters all the time a professional sporting events and well all shoot at the same exposure settings.

Indoor basketball we all shoot at 1/500th second @ f/2.8 with an ISO of 3200

We all shoot in RAW

Because they're two different cameras.

Sounds to me as if the lighting was less than you expected. If it was out doors then you certainly shouldn't have needed ISO at 1250.

1/400 will come pretty close to stopping the action but you could also need more f/stop. 2.8 isn't all that large. Underexposed by 1/3 stop, how do you know it's 1/3rd? And if it is it makes my case for a faster lens at f/1.8 or so.

The canon could have been over expose by 1/3 stop and the nikon properly expose and the your monitor
is off

your quote "No. It's indoors, it's in the gym. And I know that it's underexposed by 1/3 stop because it's looks underexposed and the CAMERA METER SAID SO" if the camera meter said it was underexpose then it was underexpose either open the aperture 1/3 or slow down shutter speed by 1/3 stop.