The only sense I can make of it is if the honourable prof has forgotten that the SCR is s/c after trigger.
Waveform o is the waveform I would expect to see across the load.
So he may have been confused and thought it was across the SCR, ie. wrt to the cathode, then it explains the second charging (like the second coming), ie. C would be charging towards it.
The o waveform I would expect is the lower one. It is the voltage at the anode of the SCR wrt the cathode.
There won't be any "second coming" in my opinion.
Len