Is the talk's central idea that abstractions are bound to leak and we'll just have to deal with it? I did skim through the beginning of it, but then Youtube's player suddenly skipped to the end and stopped, and I moved on.

The thing is, SQLAlchemy's SQL Expression API is a suitable-level abstraction: high enough to be useful, but not high enough to guarantee leaks. I'm happily making queries with one-liners, and haven't had to circumvent it yet, but I bet I'd have run into trouble with any ORM already.