It's not physically unsafe apart from the potential CNS depression if you really take enough downers together like that as was said, but if you don't know what you're doing (as in: by having experience with numerous trips without heavy drinking or other drugs, and gradually trying some more) your behavior and instability may put you in dangerous situations. Well even if you are experienced that is a risk just the same, but you'd likely keep a bit more of an eye on limiting your alcohol and other drug intake. Having some bad experiences can teach you nice lessons that way, but if that happens a bit gradually over time, they should at least be lessons you can afford.
Oh I see I misread, you took a shot not a lot of whisky. Even without any alcohol whatsoever, you can black out from benzos and really should be careful with recreational use of them in general and especially in combinations. I virtually never take benzos just to get high, but used to self-medicate with benzos. I once took a bit too much xanax while tripping on acid and blacked out for days and did really stupid shit. I do not know if I somehow took more once I blacked out to make the blackout that long for a short-acting benzo or what is up with that.
Smoking weed and drinking is of course fine, and with the benzos it really depends on whether you take a little bit and restrain yourself or "party" with them.