There is risk of aspiration as well, that is: choking on your own vomit if you throw up from the nausea while your gag reflex is suppressed or even unable to swallow..
I have recent personal experience with this, and just like combining opioids and benzo's it is seriously warned against but you still read about people doing it. Two things about that: that some people get away with it still doesn't mean it is safe, and also importantly it matters a LOT if you build experience with it first.
If you very slowly get used to alcohol on opioids it seems that a chance of fatal reaction is lower, though still very present.
Either way though: no it is not safe.