Fui dar uma olhada na Internet e descobri que, diferentemente de "liking", o verbo "likening (something) to" significa "comparando (algo) com".
In fact, the Michigan congressman went so far as to liken them to Judas Iscariot. (Internet)
They liken the experience to eating pot brownies, which, unlike smoking, results in more lasting, full-bodied effects. (Internet)
He generally likened a root canal to some horrible form of torture (Merriam-Webster)
I think that we can liken the two pianists, at least in terms of natural talent. (Merriam-Webster)
Poderíamos deduzir que o autor/escritor, no exemplo do consulente, empregou erroneamente "likening" quando deveria ter empregado "liking".