The fix:

// aiks_playground_inspector.cc

+ void AiksInspector::HackResetDueToTextureLeaks() {
+   last_picture_.reset();
+ }

// aiks_playground.cc

+ void AiksPlayground::TearDown() {
+   inspector_.HackResetDueToTextureLeaks();
+   PlaygroundTest::TearDown();
+ }

@jonahwilliams commentary:

I don't think this code is running in the right order. It might be torn down after we run shutdown of the context

because the dtors are running after shutdown

but shutdown is what tries to flush the fence waiter/resource manager

I want to fix this, but after some more pressing issues.