It looks suspect for Tulip Breaking Virus. Although, I see exterior damage to the outside of some buds (hail, maybe?); that can cause some localized color change, also. I'm not all that familar with Toronto and if, on occasion brush marks can appear from time to time or from one bulb source to another. Others who have this cultivar can elaborate on that aspect.
If this plant is seperated a good distance from other lilies, I would use the 'go slow' approach and watch and see what happens next year just to be sure it's not environmental. But, if it still has the same condition next year, you might as well destroy it. If it is in close to other lilies now, then I would remove it as a clump now and replant a good distance away for monitoring.
