I thought Barnes worked through both reds systematically any logically. I don't suppose any ref enjoys dishing out early baths, but the rules are what they are and players have to learn. They're not really going to get the benefit of any doubt in the current climate.
Something like that has to be looked at. Save the reds for the outright dirty but that's still a tough sanction for the reckless / careless.
I've not watched the match, or seen or read about the card offences.
I have no problem with red cards for outright dangerous play - whether deliberate / dirty, or reckless / careless. If something is frankly dangerous, then it's frankly dangerous, regardless of intent. If it's preventable, then you need the red card pour encourager les autres. Citing commissioners can then look at intent, and degree, and sort that out with bans.
Unpopular opinion: I'd be in favour of orange cards for either allowing play-on whilst the TMO sorts it out; or for more acceptable forms of "dangerous play" like thrown punches etc - a red mist descending, and needs time off to calm down. Also way better for reds as a result of 2 yellows (though I'd leave the 2nd yellow as a simple yellow, and allow the citing commissioners to sort it out later. ETA: Of course, offences that are simply not your fault should never be red - if you're standing under the high ball, and Biggar puts his knee to your head, that should NOT be a red (or even a penalty - it should be a yellow for Biggar for creating the danger).
Whilst we don't have crowds, seems the perfect time to crack down on this stuff, and get the players to change they way without "ruining" £30-80 each for 12,000 fans