A single good experience next door is real evidence, especially if the sale was recent and the home was genuinely comparable to yours. Ask your neighbour directly what the agent did well, what they would change, and whether the final price matched the original expectation the agent set.
Then widen the check. Ask that same agent for their closed sales across your neighbourhood over the last 12 months, not just the one you already know about, since a single success can be a fluke while a pattern across multiple houses cannot.
Joel Dyck welcomes a comparison against any agent's specific neighbourhood track record, including your neighbour's sale. Get your hand-reviewed valuation from Joel Dyck.