We sometimes encounter roads closed for construction (which we usually transit anyway),
but there are also errors like below...
If you got that when clicking "by bike" I wouldn't consider it an error. It was clearly passable with a bike, and might have offered a route that otherwise wouldn't show.
OTOH if it showed up as a route for a car, then it was an error, and you might send them a correction.
BTW- you didn't say, but did the step by step directions say anything about "cross tracks, go around fence"?