OK, in summary about TV's post:

- math is correct
- use of "EV" is wrong

Based on EV:

Pot = 213

cost of call = -88

% to win if villain has straight = 10/42
% to win if villain has lower set = 41/42
% to win if villain has AA45 = 27/40

AA45 (or AA35) is the best draw that doesn't have a straight already.

If villain has set or worse:
EV = -88/42 + 213*41/42 = +206

draw:
EV = -88*13/40 + 213*27/40 = +115

straight:
EV = -88*32/42 + 213*10/42 = -16

50/50 split between draw and underset yields:

x(115+206)/2 + (1-x)*-16 >= 0
x >= 0.09 (9% "bluffing")

if all bluffs are draw the maximum draw ...
x(115) + (1-x)*-16 >= 0
x >= 0.12 (12% "bluffing")
This is the worst case scenario.

Finally, if we change the draw to 8 outs and assume a 50/50 split as TV did, x >= 8%.

So TV was correct.