Originally Posted by sailingfun

Using the speedbrakes to disarm the autobrakes is almost standard practice on the 757/767. You apply pedal pressure to try and match the braking rate and bump the handle down a inch and you get a very smooth transition to manual braking.
The issue is that the FAA could consider it a configuration change on the runway which is not allowed since you are also lowering the spoilers just a bit. Normally this is done around 80 knots and has no aerodynamic effect but it has been a issue and has bit one Delta crew with the FAA.