General Rahm Kota was a Jedi Master and General during the Clone Wars and later appeared in the Star Wars: the Force Unleashed, both as enemy and ally of Galen Marek.
His Wookieepedia article states that Mace Windu met him on his home planet and brought him back to Coruscant where, despite his high age, he was accepted into the Jedi Order and trained by Master Yoda. The article does not, however, provide any explanation for why he was accepted.
Yoda himself has stated, on multiple occasions that people should not be trained as Jedi due to their high age (Luke Skywalker and Anakin Skywalker come to mind) and yet he accepted Rahm Kota who was of an age with Luke, and a lot older than Anakin.
Is there an explanation, of any canon level, to why Rahm Kota was accepted into the Jedi Order?
Direct answers are of course preferable, but I highly welcome well-founded assumptions and similar.