Astronomy Validators: Am I missing something really simple?

some-file.js

Model = Astro.createClass({
	name: "Model",
	fields: {
		height: "number",
	}
});
Model.addValidator('height', Validators.number());

if (Meteor.isClient) {
	Template.hello.events({
		"submit form": function(event) {
			event.preventDefault();
			var data = {
					height: "not a number",
					ignored: "This shouldn't show",
				};

			var instance = new Model(data);
			console.log(instance.validateAll());			// expected this to be false
			console.log(instance.getValidationErrors());	// expected to get an error object

			// same situation on server
			Meteor.call('validateData', data, function(err, result) {
				console.log(result.valid);
				console.log(result.errors);
			});
		}
	});
}

if (Meteor.isServer) {
	Meteor.methods({
		validateData: function(data) {
			var instance = new Model(data);
			return { valid: instance.validateAll(), errors: instance.getValidationErrors() };
		}
	});
}