I've never grown tomatillo so don't what it looks like, Did you ever figure out if it is one?

If you Google "tomatillo leaves" you'll get an abundance of pictures. For example ...

https://gardenerspath.com/plants/vegetables/tomatillos/ ... scroll down halfway

Looks to me like tomatillo. I've only grown them once, long ago.

It does look like one. The plants can get really large and are best planted in a 5-gallon pot or, better yet, the ground. They don't produce fruit until late summer into fall. My friend grows them in her garden, and most of the fruit are around 1 & 1/2 inch across.

I think they were tomatillo, but there were 4 or 5 and they were all getting huge, I pulled them all out. I decided I didn't want competition for Mel's Heritage. It needs all the soil, water, and nutrients in its pot.