Who are his sire and dam again? If you don't mind sharing…... And sad to say, but sometimes breeders are not totally up front with possible problems as you are seeing with Oakley.... and not because they don't want to share, but if their dogs are more or less kennel dogs than everyday house dogs, you would not see or maybe be aware of these issues... so while the answer might be, nope we don't see these problems... could be in a house/home situation it would come to light. Not saying that is the case here, but I do know that his breeders have a number of Basenjis... and I am fairly certain that they are not all house dogs, so sometimes behaviors can been missed. Kennel dogs are usually kenneled with one of the opposite sex, get limited house time... so without being able to evaluate them 24/7 easy enough to miss possible behaviors. And when in kennels, they are limited to items that could/can cause something like resourse guarding... again IMO
And that is an interesting point about a play date without you being there..... especially if he thinks you need to be the one to be guarded in a situation with more than just him...