RocketBolt always gives you whatever information it detects. If RocketBolt identifies a contact on your site and that person insists he/she wasn't on your website, it's likely one of the following scenarios (in no particular order):
1. The person you're talking to is lying or forgot. Not super-likely, but it does happen.
2. Someone entered a fake email address on your website.
3. The person shares her computer with someone else who was on your website.
4. Multiple people have access to the email address that was detected on your website.
5. The person you're talking to forwarded your email to someone else, and that person clicked a link to your website that was being tracked by RocketBolt.
While none of these events are common, they're all possible. When they happen, we encourage users to remember that RocketBolt isn't a tool that affects user actions. It's a tool that tracks user actions. When it tells you something unexpected, that's a great opportunity to analyze how people might be behaving on your website in ways that are different than what you might expect.