The areal root likely broke when you touched it a little harder than you should have - the roots are very fragile. It will still function, even after the break. The brown spots are probably a reactions to the water. Even filtered water has lots of minerals in it, and if the phal has been watered with RO or rainwater up to now, the roots will need to adjust. As long as they're firm, they're doing their job.
If the red/brown under the leaf just appeared, it may be due to excessive light. In any event, the phal needs to adjust to your environment now, and it may even drop a leaf of two in the process. Not harmful unless it's the newest leaves that are dropping.