Can you do this with a timer

2

Sure
Use the expire binding (you will have to install it if not installed)
create an unbound Switch item

Switch MyRFIDTimer { expire="1m,command=OFF" }

so… when Item GF_Security_Front_RFID received command
set the MyRFIDTimer to ON

MyRFIDTimer.sendCommand(ON)

but what we could do is check if it’s on first and open the other door if it is
so something like this maybe

rule “Access Control”
when
        Item GF_Security_Front_RFID received command
then
       if (MyRFIDTimer.state ==ON){
           // open the roller door
        }  else {
           MyRFIDTimer.sendCommand(ON)
           if(receivedCommand==“AABBCCDD”){
               sendCommand(GF_Security_Front_Lock, 1)
            }
        }
end

here is more help
Expire binding documentation

Rich explains unbound items