While I don't believe that it is a time to panic, blowing a 13 point lead worries me as much as the game itself. Playoff teams need to find the ways to win. We still don't know if this team or coach can stand the heat when the pressure is on. Despite the last two seasons poor playoff results, this season the team is better and hopefully healthy.
The Celtics rely heavily on IT but also rely heavily on the team dynamic as there is not other 'star' who can turn a game. IT, AB, JC and Horford are very consistent. It will be how KO, JB, Smart, JJ, and to a lesser extent Green and Rozier, contribute that could decide close playoff games. Amir needs to be on song too.
I don't say this single game showed it but it is vital that the team is able to find ways to turn things around quickly when the opposition goes on a run. Tough it out when you don't get the bounce. It is as much about attitude and effort as talent.