For those who did not feel like reading my article linked above about watering palms, there was one paragraph in it that specifically discusses this crown watering. I don't know if I am just the most unlucky palm grower there is, but I don't think so as I have seen plenty of cases of bud rot from crown watering in other gardens (most notably in Huntington Gardens). But, as I said in the article, there are some species or categories of palms that are much more sensitive to this bud damage than others, and after growing hundreds and hundreds of palms, and watering them carelessly for over 15 years, I have learned that there are definitely palms you do NOT want to water in their crowns in the cooler times of the year (rarely do have problems with crown watering in summer).
These palms include ALL pinnate non-crownshafted palms (at least all the ones I can grow in this icky inland southern California climate). This includes Butias, Syagrus, Phoenix, Howeas, Jubaeas, Parajubaeas, Raveneas etc. I have rotted and killed at least one of each of these this way, and some of these I have killed many more than just one (at least 3 Butias, 2 Syagrus... some seem less senstive than others, dozens of Phoenix, about a half dozen Howeas (note: seedlings seem much less sensitive than do older palms), 3 Parajubaeas (sigh), 2 Jubaeas and several Majesty palms and one R glauca). I have NEVER killed or injured a crownshafted palm with crown watering, and believe me, I have watered plenty of Kings, Rhopalostylis, Dypsis and Chamaedoreas this way and never had a single one rot on me (not from this at least).
This crown watering taboo I have self imposed also includes some palmate species, notably the blue, arid-climate ones (Bismarckias do NOT seem to be affected adversely by crown watering)... this includes Nannorhops, Chamaerops (green ones also are sensitive to crown rot, by the way, but the cerifera variety is ultimately sensitive and I have rotted multiple heads with my garden sprinklers... so no more garden sprinklers), blue Braheas and blue Livistonas (and losing one of those is a REAL drag). Never had a problem overhead watering of Washingtonias, Livistonas that are not blue, Sabals etc.
Probably one of the most commonly killed palms by overhead crown watering are the Phoenix roebelleniis, which I have seen many rot in many local gardens from lawn sprinklers (these palms are often low enough to be affected this way).
As I also said in my article, there is definitely a huge difference between rain water and tap water... I have learned this to be true with other types of plants as well (I grow a lot of cacti and succulents) and some of these are also extremely sensitive to crown watering, though much less so by rainwater. Many of these plants are reluctant to be crown watered ANY time of year, some more so when it's hot than when it's cold... no idea why other than they are plants that are from areas where there are no summer rains (Echeverias are high on this list, as are many aloe and agave species). Anyway, this is all observation, no scientific fact... would love to hear more about others experience with this.