The description for smp_send_pairreq_response on p.143 says:
"EZ-Serial will automatically accept pairing requests unless Bit 1 of the security behavior flags is cleared using the flags
field in the gatts_set_parameters (SGSP, ID=5/14) API command."
I believe that this is incorrect - it should be bit 0 of the flags field in smp_set_security_parameters, as described on p.147.
EZ-Serial BLE Firmware Platform User Guide, Doc. No. 002-11259 Rev. *C
You're correct; this has been changed internally in the draft for the next revision and will be included the next document release.