Inevitably, in reality, you don't just talk to HR. Anyone who interviews you is going to look at LinkedIn, look at other networks, and talk to people who they

Inevitably, in reality, you don't just talk to HR. Anyone who interviews you is going to look at LinkedIn, look at other networks, and talk to people who they know who used to know you. Often times the management are well connected, at least on LinkedIn... it's not realistic to expect all of the people who interview you for a new job not to contact a former employer. AND... as soon as you say, "Don't do it..." that'd be a red flag, of course they'd want to reach out then. The thing is, you'll never know what people say behind your back, or who they talk to... or if they honor your request not to talk to past employers. Only option would be to remove all traces from that company from your references / LinkedIn... and then what do you do about the gap year(s)?