Andrea Dovizioso said that Ducati factory teammate Andrea Iannone crashing into him late in the Argentine Grand Prix was "unacceptable".
Dovizioso and Iannone appeared on course to complete the podium behind race winner Marc Marquez before Iannone lost control of his bike and crashed into his teammate in the final corner of the last lap.
As a result, Dovizioso had to walk his damaged bike over the finish line, claiming 13th place, Iannone being handed a three-place grid penalty for causing the incident.
"To lose these points for us is a disaster," Dovizioso said after the race.
"[We could] be second in the championship behind Marquez, one point [behind]... it was very important for the championship because it's how I approach the race, how I approach the season - to take the best result for the championship, to get the best result for the championship.
"And this is, I think, the way to approach everything when you are in a factory team and you want to get a good result. Because we worked really hard in the last two years and we really created a good bike, together.
"And to lose the points like this is unacceptable. Unacceptable."
Dreadful end to "perfect" race
Dovizioso did say that there were plenty of positives to from the Italian manufacturer's weekend in Argentina.
"This weekend was very difficult for everybody - and we were able to manage the situation," he said.
"We were very competitive in qualifying, we start on the second row and it was perfect. And we [would've been] able to finish second in the race. It was perfect, we were able to catch Valentino [Rossi] and beat him - for the championship it was really important.
"And that was the positive thinking for the next week - fortunately there is a race very soon, in a really good, really nice track [in Austin], and we have to confirm again, in a different condition, our speed."
Additional reporting by Oriol Puigdemont