My sister got a dog from a rescue ,and he was lovely for about 3 months,then all of a sudden when she was stroking him,he turned on her and almost ripped the skin off her hand, this happened twice so she took him back to the rescue
In my eyes though the poor dog shouldn't have been rehomed without proper assessment, as the rescue had only had him in for about a week, one of the women there told her to watch her finger, anyway it really upset her to return him and a few days later she rang up to ask how he was,they told her they ha rehomed him again,
I would have reported that place. as obviously they knew he could turn, yet they rehomed him again within days
I felt so sorry for the poor dog, as i bet he was again returned