To my knowledge, the info on pitch and roll comes from the copilots ADI, then fed in parallel to the IHUMS and FDR. There are 3 ADI's on the Dauphin.
Someone mentioned pitot static input. Remember that a trimble GPS is fitted, where groundspeed can be monitored and there are two independent pitot systems.
I can't see how a pitch and bank of 38 degrees can be put to a problem with air data instruments.
The data which is fed to the FDR is calibrated every 12 months.