There is no certain delivery result to achieve from anyone in football, those you see performing well are only having the opportunity to shine their star as early as possible before things go more was than before for them, also when we see a low performance from a football club, obvious that they never wish to have such experience except when they are push to wall without being left with an option.
While he did get a draw against Liverpool, I would honestly say that this was one of the few matches he had where he could have lost and that would be ok because Liverpool is the type of team Spurs could lose no matter who was the manager, so the fact that they got a draw from this game should make him stay a few more games. But, we are getting very close to the end of the season and the fear of them dropping is very real.
Right now, there are two teams beneath them with 29 points and Spurs have only 30 points, so they could realistically drop very soon and if they didn't get a draw here, they would be equal points with relegation teams. That's not an easy thing for them and while I understand firing a coach this late into the season is tough, it's reasonable when you look at the results.