They tried, but the dot was only visible for a fraction of a second ...

I understand, low powered red laser pointers are difficult to see for people with color blindness. And the high powered laser pointers are legal only in some countries. A long stick just works.

I expect they did spring for it when the room was last remodelled, but since then for sure the batteries have died several times, some lecturer brought it with them to their office by mistake and forgot it there, and the students have stolen it.

The stick however, it remains.

The best professors I had in my time in university were the ones who didn't let technology get in the way of effective teaching. The ones who grabbed the newest technology were the ones willing to waste combined days of time (that's a big lecture hall; there could easily be hundreds of students in that class).

I guarantee the university would have let her expense a laser pointer, but those break, run out of batteries, and can be harder to place accurately or spot. Sticks just work.