I think the MD80 is one of the planes with the most amount of differering options out there. There's EFIS, non-EFIS, autobrakes or not, FMC's or not, switch locations on the overhead, TOW options etc etc. I have flown 4 MD-82's and one MD-83. 2 82's were the sisterships. One had a higher TO weight of 67.8 tons, but the units were in pounds. None had GPS-FMC's. The 4th -82 has the same TO weight of 67.8, but weights in kilo's and some switch positions wre different. The MD-83 is a HGW version which at one time was supposed to be delivered to the US military if memory serves me correct. Than planned didn't go through and there are a few out there. The have a TO weight of 72.6 tons and a MLW of 68.0 tons. That's 9 tons of extran landing weight than an -82. 5tons more than a normal -83.
The reason I say is that this plane may not have had an autobrake system. On the MD-82, the most prominent item being the RAT probe. It is the most obvious. Other than that, the cabin blower fans under the front cabin floor will stop operating. But only a lot of experience and a relaxed keen ear can detect that. If it was night time, you can also see the strobe lights flashing away on the wing tips. Other than that even though there's quite a list of inputs few may be aparent to crews. Remember also that the ground shift system abviously has a mechanical part and hydraulic part. It may be that for example that the landing gear anti retract knob which should retract when airborne, or the rudder controlled nosewheel steering which should be disconnected if the plane is in air mode, do operate as it should because electrecally the plane would thinks it's in the air, but mechanically (because the nose strut is still compressed) it is in gournd mode. I think these two systems are affected mechanically.
EDIT: If the taxi out checklist was carried out you would also have noticed that when carrying out the flight control check, the SPOILER DEPLOYED caution light fails to illuminate. In the check you verify that the light illuminates to confirm if your flight controls behave as they should. So if the checklist was carried out they should have noticed it.
Xander