"If Alexander Graham Bell, the inventor of the telephone, had been around today he’d have been quite bemused by how we’ve dis-invented his invention."
In above sentence conditional has been used. It's referring to a hypothetical situation in the Past.
This I read in context where present situation is discribe. I mean present usages of phone other than calling etc.
Refer below LInk.
According to my knowledge writer should have used conditional II type. It refers to a hypothetical situation in the present or the future (subjunctive).
So the sentence should be like this
"If Alexander Graham Bell, the inventor of the telephone, were around today he would quite bemused by how we’ve disinvented his invention."