An earlier report by Johnny Wee describes the Oriental Pied Hornbill (Anthracoceros albirostris) eating guava fruits (Psidium guajava) by picking pieces off the attached fruits and swallowing them. On the other hand, Tan Teo Seng observed the hornbill in his farm in Johor, Malaysia, picking ripe guave fruits, mandibulating them before swallowing. These are probably smaller fruits and softer, probably in an advanced ripening stage, thus soft.
In the case of the rambutan (Nephelium lappaceum), Marcus Ng reports the Oriental Pied Hornbill swallowing the fruits whole. Johnny Wee, on the other hand, observed the hornbill picking up the fruit and attempting to break the skin with the tip of its bill but invariably fails as the fruit slipped away (above).
Image by Johnny Wee.