I can't speak to the historicity of this particular event, though I would be highly skeptical of it. I don't want to get into 20 year stuff but as a factual matter Russian diplomats have since been kidnapped (and indeed killed) by Muslims.
As a few matters of context:
Reprisal killings or collective punishment of families is not regarded as a particularly effective counter-terrorism or counter-insurgency tactic, though it has certainly been tried.
Hezbollah is a Shia Islamist militant group based in Lebanon and I would find it highly improbable that a single incident in Lebanon would have an effect on "Muslims" as a whole. If I haven't heard of this incident as an Arabic-proficient Westerner who's relatively well read on this subject, why should such a thing stop a Pashto-speaking tribal in the Pakistani FATA with no access to the internet or books other than the Quran from wanting to kidnap Russians? (To give just one hypothetical example.)
Though to my understanding this would not have been true at the time, and again, wanting to avoid 20 year stuff, Hezbollah has actually got a pretty good relationship with Russia vis a vis the Assad regime and Iran.
Why kidnapping specifically? Since this incident Russia and Russians have been the victims of any number of incidents involving the deaths of Russians at the hands of Muslims. I find it highly implausible that something that would deter kidnaps would not also deter murder, and therefore am suspicious of such a deterrent existing (which, of course I noted from my link above, that deterrent does not exist anyways.)