Trycatch EventEmitter Fail

gistfile1.js

var util         = require("util"),
    events       = require("events"),
    trycatch     = require("trycatch");

function doit(that) {
    trycatch(function() {
        // Comment out this line and assign below, and trycatch works
        if (!f) f = new foo
        f.bar()
    }, function(err) {
        console.log(that)
        console.log(err.stack)
    })
}

function foo() {
    this.on('bar', this.onBar)
}
util.inherits(foo, events.EventEmitter);
foo.prototype.bar = function() {
    // EventEmitter breaks the catch function
    this.emit('bar')
    // This works though, even though it appears to be the same?
    // this.onBar()
}
foo.prototype.onBar = function() {
    throw new Error('wtf')
}

// Uncomment this assignment and assign above, and trycatch works
var f// = new foo

doit({a: 'b'})
doit({c: 'd'})
doit({e: 'f'})