Per The Ringer's Kevin O'Connor, the divide between Sixers executives and Colangelo started during Fultz's private workout with the team last June:
"It was a decision praised at the time, but after Fultz struggled in his workout with the Sixers last June, league sources say some Sixers front office members suggested that despite making the trade, the team should have taken a second look at Tatum or Lonzo Ball. But the idea was shot down by Colangelo, according to sources."
Most analysts regarded Fultz as the top prospect in last year's class, including B/R's Jonathan Wasserman.
"With Fultz's unbeatable numbers—he was the only player in 25 years to average at least 20 points, five assists and five rebounds and shoot 40 percent from three—along with the tools and athleticism to back them up, the losses at Washington can't factor into the assessment on his long-term potential," Wasserman wrote.
A shoulder injury limited Fultz to only 14 regular-season games during his rookie campaign. The 20-year-old averaged 7.1 points and 3.8 assists per game during those outings, but he didn't appear in Philadelphia's last seven playoff games against the Miami Heat and Celtics.
The Celtics wound up drafting Jayson Tatum with the No. 3 pick they received from Philadelphia. The former Duke star is one of three finalists for the 2017-18 NBA Rookie of the Year after averaging 13.9 points and five rebounds in 80 games.
Colangelo resigned as president of the 76ers on June 7 after an independent investigation revealed his wife shared private information and criticized players on the team and opposing teams on secret Twitter accounts.