This premise is wrong. The clause "he was infuriated" is in the passive voice.
That he was infuriated implies that something infuriated him. Given the context that you've provided, we can easily guess what that something is. He saw his wife and her boyfriend chatting. That sight infuriated him. He was infuriated by what he saw.
The match was started. -- a passive-voice past-tense statement
When was the match started? -- a passive-voice past-tense question
The strike is ended. -- a passive-voice present-tense statement
Is the strike ended? -- a passive-voice present-tense question
Some verbs are ergative. The verbs to start and to end happen to be two examples. In a passive-voice construction they imply that some semantic actor or agent exists, even when no such agent is specified or even suggested. In an active-voice construction that has no direct object, they do something different:
The match started.
Did the match start?
The strike ends today.
Does the strike end today?
These examples use the same grammatical forms and structures as ordinary active-voice clauses. However, they have the kind of meaning that in some other languages is expressed in the middle voice.
The verb to infuriate is not ergative. The statement "he infuriated", in the active voice and without direct object, simply doesn't make sense. Statements that do make sense include the clearly active "something infuriated him" and the clearly passive "he was infuriated".