When data roaming is off you cannot use Mobile data even when connected to a foreign network.You may be right on answering calls, sending sms or accessing voice mail will trigger the "Rome like home charge" if it's not disabled by chatting or calling...
I guess some have the time to call or like to call Rogers.Some would prefer to handle it themselves, in fact Data roaming should be always turned off, why would anyone have it turned on unless they have a roaming package. Turning Data roaming to off...
It's Roger's money making scam in the past they did have an option to turn "Roam Like home Off", I see it's not available anymore, you can turn OFF " Data Roaming", that should not automatically activate " Roam like home even when you travel" , below...