Variability for /r/
In fact the pronunciation of the informant is variable. While the third token of pangambaa (‘traveller’) in her reading of The North Wind and the Sun passage is [paŋambaa], as illustrated in Figure 1, the first and fourth tokens of the word both have a tapped [ɾ], as illustrated in Figure 2, while the second token has an approximant [ɹ].

Figure 1. A spectrogram of 1.3 seconds of speech, showing pangambaa atu (‘that traveller’) in which there is no /r/ sound in pangambaa.
Figure 2. A spectrogram of 1.3 seconds of speech, showing pangambaa datang (‘traveller arrived’), in which there is a tapped [ɾ] sound in pangabaa, probably influenced by the Standard Malay pengambara.
While this might be explained by the fact that pangambaa is a word borrowed from the Standard Malay pengambara (and the word is not in fact listed in DBPB, 2006), so perhaps it sometimes maintains the /r/ from Standard Malay, variability extends to other words. While all three tokens of utaa (‘north’) are pronounced as [utaa], with the expected absence of /r/ (c.f. Standard Malay utara), as illustrated in Figure 3, in contrast the informant unexpectedly pronounces dai (‘from’) as [daɾi] with a medial tapped [ɾ], as illustrated in Figure 4.

Figure 3. A spectrogram of 1.3 seconds of speech, showing si angin utaa pun (‘the north wind, in contrast’) in which utaa (‘north’) has no /r/, as expected.
Figure 4. A spectrogram of 1.3 seconds of speech, showing the final phrase in the passage, kuat dai kadia (‘stronger of the two’), in which dai (‘from’) has an unexpected tapped [ɾ], probably influenced by the Malay equivalent dari.
It seems, then, that the pronunciation of even common words such as dai (‘from’) may be influenced by Malay, and it is uncertain how widespread pure traditional Kedayan is in modern-day Brunei.