Anderson's starting to miss his spots a bit, it looks like. 2 BBs in the 4th and some other 2- and 3-ball counts, but he got 2 more swinging K's and got Rutherford to ground out.
He's at 59 pitches, so probably just 1 more inning for him, but he now has 16 Ks in 8.2 IP. I'll take it. The 5 BBs are a bit of an issue, but he is 18, after all.
If I had to guess, I would say it's a sign of fatigue, both mentally and physically. Keeping everything together for 80-100 pitches is one of the things these kids have to learn.