If it was just as fast to walk, then he should have walked. But by taking a vehicle into the street while intoxicated he enters DUI territory.
As for your wheelchair comment i think the context matters. I doubt they would charge someone who needs the wheelchair with a DUI in the scenario but someone just taking a motorized wheelchair for a drunken joyride down the road will likely end up with a DUI.
Canada was going to have the inequality anyway. The immigration is a scapegoat for the declining quality of life but many policy decisions outside of immigration were already impacting quality of life. The housing bubble and oligarchy/monopoly of major sectors (grocceries, telecommunications etc) are the main issues driving inequality in Canada.
Canada could support its ambitious immigration goals if it were willing to invest in the country to support them, such as extensive public transit overhauls and nationalizing essential services like rail, communications, and energy.