You're right - he was. Flex has stated that on numerous occasions. MuscleMag, Muscular Development, his autobiography book....
Which gets me, why do people believe the whole 'implants" thing. That he took his implants in and out, like soccer pad inserts, that makes no sense. It would cause major scarring, if not an infection.
Shawn admitted here on getbig, he was trying to get Flex off his game, and brought it up.
Esiclene he admitted to, so there you have it.