You kind of jump around from point to point. If your hand is wrapped around a a source of electricity (Assuming that it's not static charge and can provide a current equal to the source voltage over your bodies resistance) I'm sorry but you are not going to let go, even if you are hanging from the wire. Until a formation of soot has formed and the oils in your hands have burned off to increase the resistance, there is no letting go.
Let me give a couple of reasons why AC just as dangerous as DC.
1) Your body shares some of the same characteristics a capacitor, a capacitor with small capacitance, but one none the less. This means that an AC current can shock you without forming a classical circuit that would be needed for a shock from DC.
2) You mention RMS as a reason why AC is safer? The root mean squared voltage of AC is going to be less then the peak voltage induced by the name plate voltage. Wall socket voltage may by 120V RMS but will peak around 170V.
3) With a peak voltage of 170V the current through a resistor (like a human body) is going to be ~40% greater than that of an average 120V for DC. Stating that current kills but voltage doesn't is also ridiculous (unless you are talking about static charges). It would be like saying that the flow rate of water down a stream is dependent on the amount of water in the stream and not the speed of the flowing water. The fallacy is also point out in the link your provided.
4) Hearts are much more likely to suffer from complication due alternating current than from direct current
Again, I stand by my initial assertion, both AC and DC are just as dangerous. Anecdotal stories, while entertaining, don't mean much considering that you may have been hydrated while dealing with DC, which can increase the bodies internal resistance greatly. You may have been more grounded, you may have been touching a piece of metal that was grounded, the circuit may have been created across the chest which gives a nasty shock. There are many external variables which can alter your perception of what it feeling like while being electrocuted.