Hm. I know the -700 is often a F1 takeoff. Usually if you fly mixed fleet, you get to fly a -700 rarely. The weights and speeds always seem low. This one was a 700, was a F1 dep and on FRA's 4000m runway would probably have been an 18K with a fair bit of TASS as well. Thye rotaion was prompt so no W&B issues and probably a middle to rear trim anyway. FRA to N Africa would be 10T of fuel or so and Like a coupdl of pages earlier the most likely situation is the FZW was put in the top line of the FMC. With a good load, that would be in the low 50's and -700s do fly domestic and shorter flights at those weights, so not immediately a Gross Error item.
The crew's actions in lowering the nose carefully and waiting was safe enough, but going back to the hold for another go ant the right weight would have been safer....
I've flown a mixed fleet and with most aircraft -800s it was always a bit weird flying the sports model.