"Pump and dump" usually refers to a specific scheme when one powerful entity manipulates the price to get profit. If the price is simply volatile and has huge swings, it doesn't necessarily mean that it's been manipulated. Also it's important to look at market depth before building and suspicions - the higher amount of bids, the less likely it is to be some sort of manipulation. And even if there will be a big correction, it won't mean that it's the dump from pumpers - rises and crashes can be driven by many different reasons
I somewhat agree with your view
And somewhat disagree with it. First, you typically don't need to do anything after a good old pump, i.e. you don't need to specifically manipulate a dump. You may need to instigate an initial sell-off, of course, but then the market and hordes of panic sellers will take care for the rest of the cycle. Further, market depth can be utterly misleading, or even deceiving. You can see huge buy walls which quickly disappear once the price starts to seriously go down. These walls can be built by the exchange itself, so they can erect and remove them without any risk of losing any money (no wall has been hurt in the process of making a dump)