The circuit in question is a D-FF with asynchronous clear, the output of which is inverted at the pin. In addition the non-inverted output signal (RAS) is fed back into the internal logic.
The effect of RESET is to clear the register, which due to the inversion causes /RAS0 to be asserted (high). Thus the fitter must convert the CLEAR into a PRESET when it moves the inversion to the input side of the FF.
However, the report file shows the following equations for /RAS0:
Note that .SETF is used for RESET and .PRLD is high (VCC) as expected.
The bug will be triggered every time a register with a set/rst signal drives an inverter which in turn drives an OBUFT. In this case the software will not swap the set/rst when the inverter is swallowed by the register.