Margaret did put a lethal dose of pain—killers in the drink, in the Grand Finale
For the ‘Ayes’: 1
For the ‘Nays’:
- This troper put a nay in, at least. It is quite unlikely Margaret, as much as she's suffered, would have snapped being the strongest character in the series. Granted, she's come very close and her impassioned plea earlier in the episode really does make you believe she'll kill the maniac who ran down her husband - but that's the point. She was prepared to kill a maniac, another one of the incredibly selfish and inhumane characters they ran into all throughout the series, not a woman she became close to during their mutual grieving of their husbands. The death was an accident and a product of Glynis' own misfortune. It's no surprise that being responsible for the death of another human being on top of losing her husband would cause a shaken human being to simply run away. Glynis wasn't some sadistic creep, she was broken as well, and it's just not characteristic of Margaret to murder someone even more beaten down in her grief than she was. Even for this show, that would be an extremely cruel end to a series that was always dark but still human at its heart.
- It's also worth noting that the apparently canonical 2001 Comic Relief sketch where Victor is still dead shows Margaret still seemingly living her normal life whereas she would've been in jail for murder (and with more evidence and the fact that the Mildrews simply can't get away with anything, she would've been caught a lot quicker than Glynis would have). Even if the low string stings hinted at poison when Glynis was drinking her drink, this show has faked out the audience before and would've likely not left it ambiguous in the first place if the ending intent was for Margaret to snap and murder her friend. All and all, apart from just being obsessed with her husband's killer, there really is no evidence or much of a real motive for Margaret to poison the drink. There's just no point to it, and if the creators were wanting to reschedule the finale airing to give Victor's death dignity (which they did), they wouldn't then ruin it by making his good widow finally commit the Moral Event Horizon.
- Take a Third Option: Margaret did put a lethal dose of paracetamol in the drink, but Glynis realised. Wracked with guilt about Victor's death, she drank it anyway. As soon as Margaret had left, Glynis forced herself to throw up, then got herself to the hospital pronto. Having failed in her attempt to atone for Victor's death by trying to help Margaret, she came clean about the hit and run, faced the consequences, and never told anyone that Margaret had been responsible for the overdose.
Victor's apple tree never fruited...
... because apples can't self pollinate. They need other apple trees around to produce fruit. Shame he didn't have any bees.