It's a myth that having the source code for a cryptosystem is going to allow you to spot backdoors. Crypto flaws have hidden for many, many years in far more important projects than Tor. Crypto flaws are very subtle; you can create a backdoor in a crypto routine simply by changing the way it happens to influence the L1 cache.
I wonder how he makes the conspiracy theories about NSA when Tor is open source? He is free to investigate the source code for 'backdoors'.
Such conspiracy theories and trolling are nothing but desperate attempts for attention.