Testing for equality with zero error
Let $D$ be the distribution on inputs that w.p. $p = 1/(1+\epsilon)$ picks $(x,x)$ for random $x$, and w.p. $1-p$ picks $(x,y)$ for random $x \neq y$. An appropriate choice of random coins leads to a deterministic protocol that never makes mistakes and outputs MAYBE w.p. at most $1/2$ with respect to $D$. In particular, it must answer YES on at least $1-(1/2)/p = 1/2 - \epsilon/2$ of the nodes $(x,x)$.

Suppose that the protocol uses $C$ bits of communications. It therefore has at most $2^C$ leaves. Each leaf is a monochromatic combinatorial rectangle, and so each of the at least $(1-\epsilon) 2^{n-1}$ YES answers must end up in a different leaf. We conclude that $C \geq n-1$.