You were surprised they bent so easily? That could be BECAUSE THEY ARE NOT!
I've dealt with dozens of riders who after a minor spill thought their handlebars were bent. Much cursing usually follows the noob's fall, so upset the "cheap, crap OEM bars bent"

But what the Noobs miss is PAGE ONE in crash recovery check list:
In most falls the fork tubes will twist a bit within the triple clamps. Guess what that makes the bars feel like? Like their bent ... but they ain't.

Some bikes (like my DR650 ... and possible your TTR) have something else built in that fools noobs ... they have rubber bushes in the bar mound bolts. (helps with vibration) These rubber bush will be moved in a fall ... and they will stay moved .... once again fooling the Noob in think bars are bent ... once again ...they ain't.

Repair to "Bent" bars:
Sometimes you will have both twisted tubes and tweaked rubber bushes. OR ... you may only have one or the other.

If handlebar bushes are tweaked ... simply PUSH bar when on the stop in Opposite direction of so called bent bar. Fiddle with this. Do test rides to see how things change. Can't make progress?

Step 2.
Loosen all upper and lower triple clamp bolts. (first raise front of bike off the ground) Do not loosen so much that fork tubes fall out ... just a bit loose.
Now Jiggle bars back and forth a few times. This allow fork tubes to sort of "self center". Spin wheel, hit brake. Jiggle.

Now ... tight first lower clamp in stages ... left right in two tightening stages.
Now same on upper triple clamps. NOTE: DO NOT over tighten triple clamp bolts as fork tubes are easy to CRUSH!
follow factory toque spec on this.

test ride. No joy? Go back to pushing on bar at stop. More test rides to check.

When trial riding I simply find a convenient tree or rock ...and use it to tap front tire on to straighten fork tubes ... most times ... no need to loosen triple clamps ... but above method is preferred mechanics method.

It's actually pretty damn hard to bend a handle bar ... especially one with a Bark Buster mounted up to it. (makes it STIFFER)

Hope this helps. Tomaseli is good bar ... hope it can be saved.

It's very deceptive to try and "sight" the bar to check for straightness ... best to ride bike to get it perfectly straight. Amazing how many guys ride around with
"bent" bars ... and just live with it, when a 5 minute fix is right out there.