Tap Lines

There's a bar not far from my house where all the beer tastes exactly the same. The taps run the gamut from IPA to lambic, but they all have the same wet-shoe taste. The problem is that the bar either cleans their tap lines too much or not enough. Basing my assumption on the cleanliness level of a bathroom that doesn't have hand soap, I'd guess the latter. The other week I went to another bar near my house and the bartender set a beer in front of me. I took a sip and he said, "Let me know if it's okay, I just cleaned the tap lines." It seemed to taste okay, but how was I supposed to know if it really was? Maybe he was asking if my vision was beginning to fade or I was feeling dizzy.