[cvoss]

The issue is really focused on the grammatical function of the word. The researcher is arguing that it's not ever used as an interjection, which "whoa" always is.

[zahlman]

I would say the presence of an exclamation mark, in a context where exclamation marks are rare, is strong evidence of use as an interjection. Unless we're arguing that some other mark was mistaken for an exclamation, generally I would say rare typography is "marked" (noteworthy) rather than being likely mistaken. I think the researcher's position is not likely to hold much sway going forward.

[tsimionescu]

The exclamation mark is added in transliterations of the manuscript because it is believed to be an interjection. If you look at the manuscript, there is no such mark: https://en.wikipedia.org/wiki/Beowulf#/media/File:Beowulf_Co...

[Sharlin]

Why would you assume the original had an exclamation mark? Indeed the whole symbol was not invented until the 1300s.