It was a shitty pass, I agree, but Busquets could have reacted better.
EDIT: I watched it again now. Yeah, it definitely is Busquets mistake. When Ter Stegen makes a pass, Busquets looks away from the ball for a moment and that half a second is enough to lose the ball. Very slow reaction, just like many others in recent games. Although I will say again, it wasn`t a perfect pass from Ter Stegen either.
I'd say 35% fault goes to TS, 65% of fault to Busquets. Or a distribution along those lines.
A video:
https://www.youtube.com/watch?v=pblph2q2YGI
When Mats passes the ball, Busquest is surrounded by 3 Celta's players.
Ok, he has time and space to receive the ball and pass it further, but still...
On the right, Pique is making himself available and there are no players around him.
Further on the right, Roberto also seems to be alone, unmarked.
Further, what can't be seen right away, on the left Mathieu is making himself available and unmarked, and when Busi loses the ball, we can see Mathieu entering a sight of camera (in the right bottom corner of the screen), running from a position where he expected a ball from Mats.
Now, people will probably reply: but this is how Barca plays, we keep possession, plays some risky passes and that's it.
But, but, but, there is a difference about WHICH player is making a risky pass.
If Messi has the ball in the final 3rd, and he tries a risky through ball to Suarez or Neymar:
= he will either create a sitter for Neymar/Suarez, or the ball will be intercepted since it was risky
So, what will happen when Messi plays a risky ball?
= let's say 30% chances for creating a sitter
= and 70% chances to lose a ball
= and 1% chance that the opponents will create a deadly counterattack after his mistake/lost ball
When a midfielder has the ball, let's say Iniesta or Rakitic, and if they try a risky pass:
= there is 20% chances for creating a chance (let's say lower benefits than in Messi's position since more defenders are able to intercept the pass)
= 80% chances for a mistake (bigger chances for a failure than in Messi's case)
= plus, now we have a higher chance for a counterattack when a Cm loses the ball, than in a case of a Rw losing the ball
-- let's say that a chance for a deadly counter is 20-30% now, in this case
So, you see, when a Cm tries a risky ball, chances for benefits are lower, and chances for a deadly failure/counterattack are higher and higher
If Busi tries a risky ball and loses it:
= possible benefits are even smaller
= and a risk of a deadly counter is even higher since only 4 Barca's players are behind him
If a Cb makes a risky pass:
= benefits are extremely low, more or less
= chances for a deadly counterattack are extremely high
Now, let's go to a Gk:
= when he makes a risky pass, potential benefits are extremely low (except that we will keep the possession)
= and potential risks if he will lose the ball, or if a player who receives a pass will make a bad first touch or something=are extremely high
So, yes, risky passes are Barca's style.
And all players are doing them.
But again, there are differences in benefits/counterattack ratio when a Rw, Cm, Cdm, Cb and Gk make risky passes.
Some basic logic should say that Messi, Neymar and Suarez should be allowed to try the highest amount of risky passes, since the potential benefits are huge (they have good playmaking abilities plus they can create a 1 on 1 for a teammate) and potential risks are low, since 7 of our players are behind the ball if we lose the possession.
Cms should risk less than attackers.
Dcms even less.
Cbs even less.
Gks should risk almost never.
And then, we have a guy like Ter Stegen who doesn't understand that a risky pass from Busi to Iniesta and from Iniesta to Neymar is a less dangerous than a risky pass from Mats to Busi, when Busi is surrounded by 3 opponents, while 3 of our players are completely free and unmarked (Pique, Roberto, Mathieu).
My personal estimation of who is guilty for the 1st goal:
Mats 80-90% because of a stupid choice of whom he will pass
Busi 10-20% because of a poor concentration and a poor first touch
But Mats created a shit in the first place with unneeded dangerous passes.