That's not original adaptor but something homemade. By the looks of it the surface isn't flat or straight to make a decent seal. It looks like the threats of the connector did not went deep enough and it was only holding by 2 or 3 threats. To make it seal you have to tighten it pretty hard. It is only a matter of time before the threats gets stripped. Be glad it happened in your garage and you spotted it on time. Not while driving.
These adaptor for the oil coolers or oil filter relocation are cheap, I would just buy one.
Search for a Universal Perma-Cool Bolt-On Oil Filter Adapter # PC195
Those are very cheap.