Not sure if Doc is really blaming the refs for the loss (he did mention that his team looked "fatigued") but he was not happy about the officiating.
"Looking at [the box score], I thought it was a miracle going over the game tonight," Rivers told reporters in San Antonio. "Listen, they go into the fourth quarter with six fouls total? That means they are one heck of a defensive basketball team, they were terrific." When a reporter quipped that Rivers appeared to be dripping with sarcasm, Rivers admitted his frustration. "It was being sarcastic, but, listen, what can you do? It is what it is," said Rivers. "They shot more free throws. Two of our free throws were [the result of] technicals, so we really didn’t even get that [many]. It’s hard to win games on the road when teams go to the line like that and we don’t go to the line."
That's part of the coach's job, to get on the refs. But I don't think the refs won or lost that game for either side. "It is what it is" is right.