I also agree that mirror site is better to use if they experience difficulty of accessing their casino. But they should ask the link from their support so that they would get the exact link and not the scam came from random people online. But didn't heard that Rollbit had a mirror link but I guess they occasionally give this to their gamblers.
This is a great point right here. Many people fall for scams by going to random mirror links and end up blaming the main site. Gamblers should always find out legit mirror links through customer support before using them.
This is what I have been doing across a bunch of sites over time and I never faced a single issue. Some sites like Stake even display official mirror links in an organized manner.