As far as we aware, no
e-liquid manufacturer uses actual tobacco smoke to flavor their product. To do that would involve the combustion of tobacco and then dissolving the smoke in a liquid, then using this as a flavoring. Since there are many standard alternatives to this unusual procedure, it is unlikely. 'Smoke' flavors are a universal additive in foods (think smoky bacon, smoky barbecue flavors), and food flavorings provide 99% of those used in the e-liquid trade at present. Almost all commercial flavors come in the form of synthetically-produced chemicals or basic flavor ingredients processed from an organic source - these, found in a Dekang e-liquid ingredient list, are typical:
3-Methylcyclopentane-1, 2-dione
Piperonal
Damascenone
Acetylpyrazine
Rhodinol
Eleutheroside E1
...because they are widely available and often far cheaper to produce than actually burning something or whatever else the flavor is required to reproduce.
I would tend to think that your 'lifelike' tobacco flavor supplier has done a good job in replicating the effect so well. On the other hand, some might prefer to use such flavors only if they are organically-derived, as is the case for TA for example - Tobacco Absolut, a concentrated tobacco flavor extracted from the plant by distillation, and popular in DIY tobacco liquid recipes because the commercial chemical flavors are not available in small quantities to the public. (Some DIYers also produce their own version of TA, which they call TE or tobacco extract/essence, by means of boiling tobacco in VG - the end result is the same or similar to TA. This being ECF, we even have a sub-forum for it...)
Therefore, as you can see, there are two main routes to getting a tobacco-flavor result: using the individual chemical components or using TA (plus the DIY version of it, TE). Both are widely available to the trade. Dissolving tobacco smoke in a liquid is not known to be currently used, as the same result is widely available, most likely more cheaply, from the standard suppliers, or even by DIY. Additionally, a supplier would not normally use a method with the obvious health implications this has.
p.s. I guess we'd all like to know exactly what the great-tasting tobacco liquid is, it's something of a holy grail for some people and they never find it, the theory being that it's impossible to replicate burning tobacco exactly with an e-liquid. PM Lightgeoduck the Mod in charge of this section, he'd probably like to know too.
