A few reasons why your analogy is flawed. First, M0 (which is one of the more conservative definition of money, is about 4 trillion, so the value loss from a billion dollars is not going to be anywhere near 10% to start off with). Secondly, by printing money you're again only affecting M0, but there are a lot of debt-based instruments that are probably better characterizations of "total money", but since they are debt-based it creates some level of 'springiness' to the total money supply.
Finally, it's not clear to me what you mean by 'functioning properly'. Even if a small change triggers a bigger effect (it will, these things are categorized by cascading effects) - Is the market coordinating individual values with prices? Probably, it is: it's just that the individuals' value systems have gone a bit out of whack in a spate of mania. But who are we to judge if people get a little silly from time to time?
1. printing a billion dollars should be approximately just as [in]significant to USD supply as the 30k BTC to the BTC supply in circulation; that's why I said a billion, but not a million or a trillion;
2. market fluctions over/undershooting any corrections is reasonable, but not exaggerating them by multiple orders of magnitude - it may react to a 0.1% change as a 0.2% change, but not as 10% change;
3. a market that's "functioning properly" would be expected to correct for so huge overexaggerations - if some people get a little silly from time to time, then the market should (and would) take their money from them; but if most of the people get very silly frequently, then that's not a properly functioning market.
To add onto your analogy, if they government did print billions more than normal, then investors would project that behavior out, try to figure out what was wrong, and exasperate the effects.
Similarly, if USA government had now started to do sales like this (and larger) every other day, then it would be grounds for some major effects - but they are not; the government does not have many more bitcoins in custody, they have a few limited amounts like this one of less than $20m. Why should such a comparably small sale cause any market disruption? If some $20m re-entering the market does that, then that's a sign of a very, very small and illiquid market.
If any real scale business would start using BTC, gets a few thousand BTC in sales, and wants to swap them to another currency - do they have to think of themselves as 'market influncer' that should be careful on how to sell them so as not to rock the boat; instead of simply immediately getting the current exchange rate for that?
If US treasury prints a billion dollars, then that doesn't trigger a 10% drop in value of a US dollar - it's a comparably tiny change with a tiny effect; similarly an extra 30k BTC is not by itself a reason for large fluctuation if the market is functioning properly.