You can signal right if taking the third or fourth exit:
To Turn Left ( taking the first exit)
signal left and approach in the left-hand lane*
keep to the left on the roundabout and continue signalling left to leave.*
Use of your nearside (passenger) door mirror ensuring no one is on the left...
By signalling right on the approach would suggest he was taking the third or fourth exit. Sussex Road and Hazelgrove Road are both the B2112 which probably meant he shouldn't have made any signal on approach to the roundabout though he could have approached it in the right hand lane. Obviously...