Outside of the decisions themselves, there are two discrete issues to consider imho.
The first, which I suspect we all agree on, is Forest's post on X, for which they need the book throwing at them. After the Karl Henry debacle, whether the FA have the ability to make it stick is a different matter.
The second discrete issue is that of bias - both real bias and apparent (perceived) bias. As well as reffing grassroots, I work in professional sport, and am involved in disciplinary matters. Apparent bias is, or should be (it isn't always!) a serious consideration when sporting regulators are discharging their functions, officiating and discipline being two key functions.
This issue has been considered in horseracing (
https://www.britishhorseracing.com/...03/Christopher-Quinlan-QC-Report-29-09-16.pdf for those who are struggling to sleep), but the test of apparent bias can be summed up as follows:
Would a fair minded and informed observer, having considered the facts, conclude that there was a real possibility the tribunal/official was biased?
As a few of us on this forum do, I regularly referee games where I'm alive to the issue of bias, either because I'm refereeing my son's team, or a team I help coach, or a team my son used to play for. I always inform the opposition coach of this in advance of kick-off, as I accept I'm going to make decisions they don't like and I don't want them to find out afterwards about any possible links and then accuse me of bias. Telling them in advance won't necessarily prevent this, but it at least addresses the issue head-on.
In the professional game, on the one hand it would seem sensible for PGMOL not to appoint officials to games where their could be a question of apparent bias. However, taking that to it's ultimate end, if a referee supported any Premier League club there could possibly be an issue of apparent bias in many, many matches given how results can impact other teams in all sorts of ways. I'm guessing it's for this reason the PGMOL did not accede to Forest's pre-match request for a change of official because a) it would open the floodgates and b) taken to it's logical conclusion I doubt there'd be too many Premier League referees left available.
I don't know what the solution is, but when Forest get charged, I wouldn't be at all surprised if these points are raised in the hearing and that it's going to be a topic that is subsequently addressed between PGMOL and Premier League.