Is it safe to make chicken stock, forgot to turn crock pot on!
Bone broth is supposed to be cool when you add the vinegar to it. And then it's supposed to sit up for a half hour or so in order to let the vinegar draw the minerals, etc., out of the bone. So really at the time of this writing you've let the stock, which has already had all potentially harmful micro-organisms neutralized by way of boiling, sit up for just a few additional hours. On top of that, in order to make a good poultry bone broth you're going to bring it all to a boil again and let it simmer for another 24 hours. There's no chance anything bad is going to survive that onslaught. And there's no way mere stock, fresh off its cool down cycle, has had a chance to take in any new micro-organisms capable of forming the kinds of toxins which aren't resistant to such treatment. You're fine. And hats off for going paleo!

[EDIT]

By saying that the stock hasn't had a chance to take in any new micro-organisms capable of forming the kinds of toxins which aren't resistant to such treatment, this really is to acknowledge that some micro-organisms cannot be destroyed by boiling and, as pathogens, are the by-products of bacterial growth; since your stock has not had the time/opportunity to engender or accommodate bacterial growth, (thus the term new), there can be no reason to anticipate a consequent whose known antecedent is lacking. No new bacteria, no possibility of new toxins ...unless introduced from some flukish or otherwise uncommon manner of uncarefulness, (a cat's paw?), which would be a whole other matter. It is almost always possible to imagine contingencies which, for their very particulars, disallow of what would normally be sound advice.