Here's something; How often has this ever actually worked? Because I look from the Anime, to the Manga, to the special movies, and other incarnations, and Gae Bolg has either failed to kill the person, been blocked or negated entirely. For a guy who's supposed to have an 'auto-win' attack, he fails to actually win anything with it. Not only that, but Shirou has been healed completely after being struck with it. So clearly, it doesn't work as it's supposed to.
Whatever occurrences led to Gae Bolg being ineffective on its target or the target recovering from it throughout Stay Night had to do either with extreme luck from the target (Saber), having a means to counteract the spear's properties (Archer) or those with fatal wounds being healed yet still being cursed with the spear's effects to the point where whatever scars it inflicts don't heal up until Lancer's death (Shiro).
And since Haseo can't actually be killed or put down if his HP is "zero", it doesn't matter anyway. Haseo is Skeith, as such he can't be killed by such means. Plus, Skeith's sceptor is a one-hit kill as it automatically data-drains whomever is struck. It's what happened to Orca when he tried to fight Skeith.
What is it with you wanking Haseo? The guy ain't an abstract or a freakin' god in the World. For as much power as Data Drain gives him, he's still a glass cannon and is nowhere as durable or fast as your delusional little mind makes him out to be. As Fehafare and CerusCerenade have discussed, your so-called calcs over Haseo's speed are based on vague storyline elements.
And I'm supposed to take your word on any of these calcs I have not seen put to any kind of debate as opposed to those I did myself using the proper tools and measurements of data? Sorry, but I take my word over yours in this respect.
If no one agrees with you (as me and the other two are), whatever ideas you think you have on certain characters and fictions will fall flat.
And considering what infamy you have in battle forums, have fun getting anyone to care for what you say.