Oh, I'm sorry. I wasn't clear regarding the breeder's attitude. It sounds like she knew there was something going on if she was giving him to a rescue. This doesn't make any sense to me and has me feeling suspicious about that breeder.
Could you contact the rescue person and ask specific questions to put your mind at ease in case you needed to return him? Would that make you feel more comfortable? Do you think you would be able to come around if you kept the little guy? Sorry I can't be of more help to you. It's such a personal decision. I lost my Millie just over 1 month ago and there is no way that I would be ready now. I would need more time to acclimate to my new situation 1st and to digest the past. I have had neighbors and friends come by with their dogs just to see how I feel about other dogs in the house. I'm ok with visits, but am not ready to start all over again with a new one. Training, socialization, vet visits. I'm feeling gun shy right now since the loss is just too fresh in my mind. I will in the future for sure. I hope you will be able to find your answers soon.
Mom to Millie, Roman, Snoopy & step sister to O'Boy