A solo player cannot over taunt, but that mechanic is in play if there are taunts from multiple sources being applied, where it'll ignore it and attack whoever if players are fighting over the taunt status.

Some bosses have attacks that ignore taunt. If a DPS starts complaining about said attacks just let them know about that.

If you were in a random dungeon you might have found a PvPer actually using clench on a frost staff.

Spamming 3 taunts will not fix your issue (it will make it even worse), if you want to lock the taunt on you you have to do the following:

1) Taunt Once, never taunt again until 12 seconds are passed (3 seconds of taunt left)
2) Reapply Taunt when you have 3 OR LESS seconds left from previous taunt
3) Any player taunt (willing or not) and he'll get taunt
4) You taunt again, overtaunt will still not be a thing until here, you will proc it now tho and nobody else (including you) will be able to taunt for 12 seconds (but it's ok since your taunt here will last 15)


If you do like you say you would:

1) Taunt once
2) Taunt Twice
3) Taunt 3 times
4) Another player Taunts= he gets taunt and proc overtaunt because the condition is "3 or more taunts from 2 different sources" and he's the second source, your previous 3 taunts only meet the first condition
5) You (and nobody else) can't taunt back for 12-X where X= the amount of seconds passed between 3) and 4)