according to google tasers have around a 40% failure rate. They are fairly close range and the prongs need to actually stick into the target to neutralise them. I believe officers are taught to use two hands for firing their gun so they most likely pick a taser or pistol not both.
A lot of the anti cop sentiments come from the US where cops are much worse. It seems some australians dont understand that police are trained here for much longer, training is of higher quality and they dont need to worry about the constant threat of handguns or rifles. They just read reddit and facebook and follow the yanks blindly with no critical thought whatsoever, just an angry fantasy.
I believe in this case it wouldnt have made a difference. The officer would and should have chosen lethal force even if they had a taser. There is a greater chance of a failure with a taser vs a handgun and faced with a murderer with a machete? It would be foolish to take that chance.
Turn out in 1770 there was a solar flare between September 16-18. He apparently named the island in June so the timelines dont match exactly from what we know but its a possibility.