Only the resmoke testcase should wait on the process, otherwise the return code my be inaccurate.

In short, 
process=subprocess.Popen(["sleep", "10"])
p1=psutil.Process(process.pid)
p2=psutil.Process(process.pid)
p1.kill()
r1=p1.wait() # r1 is -9 (SIGKILL)
r2=p2.wait() # r2 is None