Urgot ultimate gets instant recast when used on Tryndamere

Whenever Urgot uses his ultimate on Tryndamere with ultimate active, Urgot will not be able to wait for a recast but instead he will instantly pull Tryndamere in. This of course having no effect on Tryndamere as he will simply survive the execute. Not sure if it only happens when Tryndamere is at 1hp and taking (otherwise lethal) damage, but this bug happens 9/10 times.

To reproduce: Make Tryndamere use ult when very low on health (maybe deal some damage until 1hp) > Use Urgot ultimate on Tryndamere.