Quoting from the actual rules (not the "rules summary"):
"Once all players finish their final turns, tally the points on your scored cards."
Angus_Khan: 5×1 + 5×2 + 1×3 = 18
JoysJoy: 6×1 + 3×2 + 1×3 = 15
"Whoever collected the most "1" cards receives a 3-point bonus."
Angus_Khan: 5 "1" cards, +0 points
JoysJoy: 6 "1" cards, +3 points
"(In case of a tie, each tied player receives 3 points.)"
This applies to a tie in the number of "1" cards, not to a tie in total points. There was no tie, so we can ignore. It's useless in 2-player games anyway.
"The player with the most total points is the winner."
Angus_Khan: 18 + 0 = 18
JoysJoy: 15 + 3 = 18
"If 2 or more players tie for the most points, they share the victory."
That's the case here, so the final result is a draw.