In an online forum a frustrated ASL student stated:
"The instructor was Deaf so I know it was being taught properly,"
To which I reply: "Not necessarily."
It is amazing how many (untrained / unskilled) ASL teachers there are (both
Hearing and Deaf) who got their job simply because they were in the right place
at the right time when a clueless hiring director (Chair / coordinator / program
manager) needed someone (or worse -- "anyone") to fill a spot.
Just because a person is "Deaf" doesn't mean they know how to teach ASL any more
"properly" (skillfully / successfully) than being Hearing makes a person
qualified to teach English.
Knowing how to "do" something and knowing how to "teach" something are two
different skills.
Notes:
Also see: Is it okay for people who can hear to teach sign language?