If it was just Turris rising like a Phoenix from the ashes, it wouldn't be concerning. If it was just his comments about the NHL not being a development league or old quotes about "don't give me that, 'oh, I don't have my confidence'" in a vacuum, probably not a game breaker though seriously concerning for this rebuilding club.
Eriksson was in and out the lineup, and on the fourth line until Les Jackson intervened. Blossom the same season after the mandate. Coincidence? Probably not given the comments both parties made about confidence and the impact on development.
Mueller had 4 goals, 17 assists in 54 games bounced around the lineup under Tippett. Same season post-trade has 9 goals, 11 assists in 15 games for Colorado before having his brains scrambled. Unreal post-trade bounce? Possibly, but concerning given other incidents.
Passed on Tyler Johnson completely. So did Minnesota (Yeo? Too lazy to look up who it was at the time) who saw him up close, but it's another name for the pyre under Tippett. Not super worrying by itself.
Speaking of funereal pyres, chosing the corpse of Langkow over Turris, only to see Turris explode in Ottawa for more goals, one less point in 49 games than Langkow had in 73 games. Very concerning. Especially since Turris got immediate praise for his two-way play as well. Another eval and usage failure. Possibly the biggest along with Eriksson.
Dvorak is a better two-way player than Waltsson on the same team in London. In the NHL so far, Waltsson looks good getting solid minutes in Calgary. Dave Tippett rules Dvorak not good enough for NHL. Extremely questionable.
Ignoring the "in progress" players, that is still a pretty damning list of failures due to evaluation and/or usage, imo. Can you name another NHL coach who had that many misses on young talent? Lots of coaches have missed on one guy the caliber of Eriksson or Turris. How many missed on more than one under their immediate care? Honest question, because I can't think of one.