No, they should have used a standard process for general resolutions and not special cased it. Which is what they did. They have a constitution and a democratic process that requires proposals, seconding, a period of open discussion, and then a vote.

They agreed on their voting system in advance exactly to handle cases where the vote might be contentious.

The "Further discussion" option is meant to allow for that. Note that the options calling for a statement in support of RMS were even less preferred than "Further discussion", which is quite weird given the context so GP may well have a point.

Why do you think it is quite weird? Historically, is the "further discussion" always at the bottom?

edit: I found those, so it's not that weird, but not very common: Init systems https://www.debian.org/vote/2019/vote_002 ; Delaying Lenny https://www.debian.org/vote/2008/vote_003 ; Change to membership procedures https://www.debian.org/vote/2008/vote_002

the more controversial or sensitive a topic, the more likely it is that people will believe that more discussion is needed before a decision is reached, so i don't find that at all surprising.

No, it simply shouldn’t have been public. The DPL elections aren’t public either.

correct, but the debian rules on this issue state that only the elections are not public. there are no provisions for private votes on resolutions.

this may change in the future if enough people find that (optionally) private votes on resolutions are a good idea.