That just means there is a running process with PID 370.
In the Terminal, run the command:
ps auxw | grep 370
and see what it is.
Yes, as I have lamented many times, the Apple RunningApplications API is severely broken. Unfortunately, Apple has deprecated all previous APIs, so I have little choice but to use it. It has many failings, such as reporting an application as the frontmost application, but not listing it as a running application. And it also has a tendency to take a ridiculously long time (in the example shown, 3ms) to answer trivial queries (and in some of the cases @Tom showed, as much as 70ms). For a query that should take a few microseconds, this is an insanely long time. Keyboard Maestro complains about these because they are worthy of complaining about, but for the most part it just works around the issues.