Considering he's a founder of a race relations group, you'd think surely through his previous co-operation with the police he would have realised that by answering simple questions given to him by officers he would have been immediately cast from their suspicions.
The gentleman in this video is clearly struggling with police, pushing a gate against them, shoving and resisting officers whilst they are attemping to carry out their legal and lawful duty. He initiated all phsyical contact.
As for whether the Taser-armed officer should've deployed Taser, that's a question for the IPCC, if he chooses to make an official complaint. Officers only use Taser when they feel they are endangered, or if they have a struggling prisoner that they believe they cannot overpower and detain safely. So in that respect, as long as the PC involved can justify their use of force then this 'public outcry' is really going to amount to nothing.
"I thought I was dying and I was think 'my children and my grandchildren need me'"
Has anyone ever seen such an overreation? You were Tasered, not shot you fool.