The most straightforward way to play this would be to do a whole-tone bend on the B-string at the 16th fret, and then play the E-string at the same fret during the bend. You can use up to three fingers to do the bend, and the bending motion actually moves the fingers out of the way for your little finger to fret the E-string, so it's quite easy to play it this way.

When transcribing a guitar part with a clean sound, you can usually notice when the player switches to another string, because of the change in timbre. However, in this recording the guitar signal seems to be going through some kind of filter and/or modulation effect pedal, which obscures any subtle timbral changes.

The B string is also the string with the lowest tension (when using a regular string set in standard tuning), so the larger a bend, the more likely it is played on the B string.

The most straightforward way to play this would be to do a whole-tone bend on the B-string at the 16th fret, and then play the E-string at the same fret during the bend. You can use up to three fingers to do the bend, and the bending motion actually moves the fingers out of the way for your little finger to fret the E-string, so it's quite easy to play it this way.

(The B string is also the string with the lowest tension when using a regular string set in standard tuning, so the larger a bend, the more likely it is played on the B string.)

This recording from the 1975 Natty Dread tour features Al Anderson on lead guitar. He was not Jamaican, but an American guitarist who had attended Berklee College of Music and played in a number of (blues-) rock bands before joining The Wailers in 1974. He added a more rock-tinged sound to the band, as is evident in this solo.