Anyone who is qualified to Certify active duty police officers in the state can certify an Officer under LEOSA. This part was amended to the original bill as some states were not setting up standards and would not certify officers.
It does not matter what state you retired from if you even move to another state for Firearms Certification. Just need to find a qualified Instructor for LEO's in that state that will certify you. There are many of them out there.
The one thing about carrying under LEOSA. You have to go by the mag bans in the states you carry in. That part of LEOSA did not override any state laws in that instance. The Amended LEOSA law did override New Jerseys ban on Hollow Points. Those carrying under LEOSA Can carry HP's in NJ.
IF you want to get the best info on LEOSA go to http://hr218leosa.com/
there you can buy the class notes that will answer just about every question you would have about LEOSA. The Officer/Attorney knows LEOSA inside and out.