i tested the following code, and call statement does calling another batch, and return to the caller once finished.
echo echo inflation bat start
echo ping 127.0.0.1 ^>nul
echo echo inflation bat finish
echo return from call statement
so i suspect "inflation.bat" contain some command that run windows program in its own thread/process. or it might contain nt dos command such as "start","%comspec%", or "cmd" which create a new instance.