Love it! One of the key things to consider for pitch-poles is the Center of Effort (CoE) of the sail and its location relative to the Center of Lateral Resistance (CLR). During a downwind run, sail forces - the drag of the rig - are pushing the Center of Effort forward and to leeward of the Center of Lateral Resistance. Once the Center of Effort moves significantly forward of the CLR, the helmsman's body weight does not provide enough counterweight to prevent the boat from nose-diving.
Look at this footage from the Moth Worlds '08. As you can see, your bow doesn't have to be under water for a nose-dive to occur - although it definitely helps! In fact, you don't even need to have much of a hull to start with to be eligible for a spectacular nose-dive. In the case of a foiling Moth, the CoE is not only moving forward and leeward, but also way up from the CLR, making a nose-dive more likely.
2008 CST Composite Moth Worlds
And if your boat is just too well-behaved and won't nose-dive even if you want it to, you can always do like these Dutch gentlemen and step on the bow
29er Nose Dive