Yeah, Bob: it's odd indeed, I've even had a grass (ground) textures disappear on a baseboard while track laying (!), getting the grey basic baseboard color, while the very same grass texture was still applied to the surrounding baseboards. Had to use the replace tool to get it fixed! 
I can simply place a new mine there and call it differently, but that has two disadvantages:
If you can't delete it, shorten the connecting track to the mine and place a new one in it's place. you may have to raise the spline height a touch then re-connect the track. name it DMS 2.
I can simply place a new mine there and call it differently, but that has two disadvantages:
- since Razorback is a large route, it'll clog up the industry list using the "drive to" command, god knows how many times i'll still have to do this with other industries.
- getting two industries on the same spot will make for extra waybills that you can't do anything with.