User blog comment:Master Sima Yi/Assassinews 28-02-'13 — Assassin's Creed IV: Black Flag revealed/@comment-5638823-20130301131026/@comment-1153722-20130301132819

Haytham couldn't, but then again, Haytham did not receive full Assassin training. For all we know, treerunning had become very common for the Assassins during that age.