In Hill's version, the cuckolded husband is a monster (Cal Macaninch has a glint in his eye that would face down Dr Doom), yet very human: whether his cold savagery is simply a character flaw or the consequence of his wife's betrayal is left open, but understandable. Even the lover - also the husband's best friend, and most likely based on the author - is revealed as weak and hopeless: his seduction of the wife is pretentious and immature. In turn, this leads to questions about the wife's willingness to be led astray.
The magic of Betrayal is in leaving open questions without being blandly ambiguous. As the play continues, apparent lies are revealed to be truth, and the meaning of throwaway references (to Yeats and squash) becomes obvious. It is a simple story, given nuance by Pinter's skill of observation. The pauses - which can be patches of murderous darkness in The Dumb Waiter, are now the ambivalent silences that allow the audience to listen to their own thoughts on this unholy trinity's sexual misadventures.