Maybe he got a bit tired? Hit a wall after fighting hard to get back to .500? Not unreasonable for an NBA player to hit a dead leg period. Also, he's missing both Yao and Hayes, the better defensive front court guy in the lineup, and looks worse as a result.
Scola's defense consists of watching the perimeter drivers and passes and guessing where he can plant himself to collect an offensive foul. When there is no legit big in the paint (Yao/Deke) to effectively deter drivers or force drivers to take an extra step or two, then there is not the time Scola needs to set up outside the circle and take the charge from the driver avoiding the shotblocker. Scola does nothing else effective defensively and never has. So, with no shotblocker to play beside, he is rendered totally noneffective defensively.
