Havent seen any real info on that. Would have to see the exact timeline of the year when Tulsky and Waddell joined to make better guesses on the subject.
I do think it's pretty safe to assume Waddell was the one who kept promoting him, which is maybe even better sign good evaluation skills than the hiring.
Waddell and Tulsky both joined in 14-15, no? Before that Tulsky wrote analytics blogs online.
Eric Tulsky - Carolina Hurricanes | LinkedIn
Even found a confirmation by the man himself. It's possible they hired Tulsky before Waddell but the gap being years is bad info