How to detect a .lock file in a geodatabase

I am very new to python, but I have written a simple python script tool for automating the process of updating mosaic datasets at my job. The tool runs great, but sometimes I get the dreaded 9999999 error, or "the geodatase already exists" when I try to overwrite the data.
The file structure is c:\users\my.name\projects\ImageryMosaic\Alachua_2014\Alachua_2014_mosaic.gdb. After some research, I determined that the lock was being placed on the FGDB whenever I opened the newly created mosaic dataset inside of the FGDB to check for errors after running the tool. I would like to be able to overwrite the data instead of having to delete it, so I am using the arcpy.env.overwriteOutput statement in my script. This works fine unless I open the dataset after running the tool. Since other people will be using this tool, I don't want them scratching thier heads for hours like me, so it would be nice if the script tool could look for the presence of a .Lock file in the geodatabase. That way I could at least provide a statement in the script as to why the tool failed in lieu of the unhelpful 9999999 error. I know about arcpy.TestSchemaLock, but I don't think that will work in this case since I am not trying to place a lock and I want to overwrite the FGDB, not edit it.