I no longer remember what motivated me to do this, but last December, I decided to take my level 1 Draenei Shaman, Slöth, get her to level 5 (the lowest level at which you can learn fishing), and then attempt to get both Old Ironjaw AND Old Crafty before reaching level 6.
I caught Old Ironjaw - TWICE - within my first 100 skill points, on 27 Dec. 2010. The details of getting into Orgrimmar at level 5 (multiple times, as I did have to train all the way up to Illustrious Grand Master) are unimportant, as I'm sure everyone has their stories, but over time, I fished at three different spots. The third spot, in the Goblin Slums, got me the least attention and harassment from Hordies, and is where I finally caught Old Crafty today, 12 Nov. 2011, with a fishing skill of 474.
Now, I'm sure I'm not the FIRST person to ever get both achievements at level 5, but I'm sure there can't be many who've had the ambition (or boredom) to do it.