Had this bathroom today with a large amount of tile everywhere walls,floors. I alway use the IR camera around shower stalls just for the heck of it knowing the reflective value of tile is not going to be very accurate. Today I actually observed a cold spot on the floor just out side of the stall and moved around at different angles and the spot stayed the same. I even tried two different palettes with the same results. So I am thinking perhaps a leak perhaps a reflection. No guessing here luck on my side, Raised floor and when I entered the crawl space low and behold the shower stall pan was leaking.
Still not convinced If I was seeing a reflection or actually had water between the sub-flooring and the tile on the floor. All I can say for sure is the drain pan was leaking
The Neo-Angle shower pans are noted for having leaks in the doors, the doors actually fill with water and leak. or when the door is opened after the shower it will leak. furthermore while taking a shower the threshold will leak, spilling water on the floor in the area your IR camera is detecting. My two cents is be carefully in your wording is the pan leaking or the caulking bad and water intrusion is noted or could the door be leaking. The pan and drain may be perfectly fine.
I love the cameras