Actually, it seems to crash here.
Which would mean that this would already crash:
from maya import cmds
reference_path = r"path/to/output.ma"
_scene_type = "mayaAscii" # or "mayaBinary"
cmds.select(all=True, noExpand=True)
cmds.file(reference_path,
force=True,
typ=_scene_type,
exportSelected=True,
channels=True,
constraints=True,
shader=True,
expressions=True,
constructionHistory=True)
Does that crash in your maya session? If so, sounds like a Maya bug.