Rashi on Numbers 15:24/רש"י על במדבר ט״ו:כ״ד

1ואם מעיני העדה נעשתה בשגגה — This means: If it is by the eyes (the leaders) of the community that this sin has been committed in error, i.e., that they have mistakenly taught of a certain one of the rites associated with the worship of God that it is permissible to worship an idol in that manner, [then it shall be that all the congregation shall offer, etc.] (cf. Horayot 5b).

2לחטת — This lacks the א usually found in it, to indicate that it is not like other חטאות, sin-offerings; for in the case of all sin offerings mentioned in the Torah that are to be brought together with a burnt offering, the sin-offering precedes the burnt offering (i.e. is offered first), since it is said, (Leviticus 5:10) “And the second animal shall he make as a burnt offering,” whilst in this case the burnt offering precedes the sin-offering (Horayot 13a).