Not at all.  There is a great deal of psychological research that shows how our human minds try to find patterns that aren't really there.  A fantastic book on this topic is "Thinking Fast and Slow" by Daniel Kahneman.

IMO, the growth rate for bitcoin would need to decline strongly (or retreat over a long period) to truly invalidate the exponential growth model.  Here's a model that fixes bitcoin's market cap at inception at $500,000.  The "rationale" is that Satoshi spent approximately 2 years building it, and the market-value for Satoshi-level talent is $250,000 / year.  

http://i.imgur.com/OiKgYfu.png

I'm not arguing for this model, just pointing out that if growth slows to a more modest (but still exponential level), arguments could still be made that we are on trend.  IMO it would take a failure to reach a new ATH by 2017, or a sustained (1 year+) fall below $250, for me to say that "bitcoin growth has halted."  

...

It's so easy to be fooled by randomness.  Here's several simulations of the same underlying exponential growth model.  But instead of solving a regular differential equation to get a smooth exponential curve, I'm solving a stochastic differential equation that adds process noise.  The people in Alternate Universe #1 who get to ride the upper purple curve will think bitcoin is the most fantastic thing!  The people riding the bottom blue curve are going to make up story after story about how it's failing.  But in all cases, the only difference was randomness.