There's no single definition of strong with respect to typing, but I would probably put Java into the weaker of type systems, though it has gotten better over time. You can usually tell by how many casts you see in the code, and with most java codebases I see them everywhere. The pervasive nulls and untyped arrays are also huge red flags.
It's also static, so your types declarations will replace tests.
But it's extremely inexpressive, so you can declare very few properties, and so it will replace very few tests.
And it's inflexible, so it will get on your way all the time while you program.
Anyway, I can almost guarantee you the GP wasn't talking about Java.