I don't know where you're getting your information but it's a good thing you came here first....
Considering that the precipitated withdrawals that everyone fears so much (and rightly so) are only an issue when going from full agonists --> buprenorphine, the only "issue" going from buprenorphine back to your DOC, be it heroin, oxycodone, hydromorphone, oxymorphone, morphine, etc...
Whatever your DOC, (in this case "dope" which I presume to mean heroin), extended use of buprenorphine is designed to jack up your tolerance through the roof due to it's incredibly high and notoriously underestimated potency.
Similar to the concept and prescribing practices behind a blocking dose of methadone hcl, half the point of the Opiate Replacement Therapy (ORT) is for your opioid tolerance to be too high for you to even consider attempting to break through your dose. This is because the amount of your DOC, in this case heroin, necessary to break through your buprenorphine dose, is supposed to make it pointless...
However in your case, 1mg buprenorphine taken via the sublingual Route of Administration means you'd be lucky to see 350 micrograms actually hit your bloodstream, which is by no means a blocking dose, but it may very well have had an influence on your tolerance.
So is it ever really "safe to shoot dope?" No, but to answer the question I think you meant to ask, is no, I don't think that an acute dose of 1mg buprenorphine via the SL route will significantly have an impact if you were to administer a full agonist of choice.
However this should go without saying that if you had the patience in you to wait another 12, even 24 hours for the remaining buprenorphine to get off your opioid receptors, it would give your DOC a snowballs chance in hell at binding to an opioid receptor producing your desired effects... Do not take this to mean that I condone the abuse of controlled substances, if it were up to me I would ask you to reconsider.