R v Nedrick:
Where a man realises that it is for all practical purposes inevitable that his actions will result in death or serious harm, the inference may be irresistible that he intended that result, however little he may have desired or wished it to happen
R v Woollin
The jury, should be directed that they are entitled to find the necessary intention if they feel sure that death or serious bodily harm was a virtual certainty - barring some unforeseen intervention - as a result of the defendant’s actions, and that the defendant realised such was the case, but should be reminded that the decision is one for them on a consideration of all the evidence.
It's a subjective test.. so if he threw the thing knowing people were there then any jury will find that he foresaw gbh as a virtual certainty of the act.
It's probably worth linking really serious harm with the description of what he threw over - if it was "very heavy" then that's justification for really serious harm.
It wouldn't go into s.18 just because there's a death. It would be, if anything else, unlawful act manslaughter. If I had 1.30 in an exam then that's the key. Otherwise, it's just murder.
I'm not sure whether they would go for battery or s.18/s.20 for uam.